9. Gastrointestinal Tract

Authors: Dahnert, Wolfgang

Title: Radiology Review Manual, 6th Edition

Copyright 2007 Lippincott Williams & Wilkins

> Table of Contents > Gastrointestinal Tract

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Gastrointestinal Tract

Differential Diagnosis of Gastrointestinal Disorders

Acute Abdomen in Child

• Intussusception

• Appendicitis

• Obstruction (previous surgery, hernia)

• Acute gastroenteritis

• Basilar pneumonia

Gastrointestinal Hemorrhage

Mortality:

approx. 10%

• Barium examination should be avoided in acute bleeders!

Source:

• UPPER GASTROINTESTINAL HEMORRHAGE

  • = bleeding site proximal to ligament of Treitz

  • @ Esophagogastric junction

    • Esophageal varices (17%): 50% mortality

    • Mallory-Weiss syndrome (7 14%): very low mortality

  • @ Stomach

    • Acute hemorrhagic gastritis (17 27%)

    • Gastric ulcer (10%)

    • Pyloroduodenal ulcer (17 25%)

    Mortality:

    <10% if under age 60; >35% if over age 60

  • @ Other causes (14%):

    • visceral artery aneurysm, vascular malformation, neoplasm, vascular-enteric fistula

    Average mortality:

    8 10%

  • Rx:

    • Transcatheter embolization (method of choice) abundant collaterals except for postoperative stomach

    • Intraarterial vasopressin infusion (0.2 0.4 U/min)

    Prognosis:

    controls 73% of gastric mucosal bleeding; high recurrence rate

• LOWER GASTROINTESTINAL HEMORRHAGE

  • = bleeding site distal to ligament of Treitz

  • @ Small intestine

    • tumor (eg, leiomyoma, hemangioma, metastases), ulcers, diverticula (eg, Meckel diverticulum), inflammatory bowel disease (eg, Crohn disease), vascular malformation, visceral artery aneurysm, aortoenteric fistula

  • @ Colorectal (70%)

    • massive bleeding

      • Diverticula (most common): hemorrhage in 25% of patients with diverticulosis; spontaneous cessation of bleeding in 80%; recurrent bleeding in 25%

      • Colonic angiodysplasia (2nd most common cause) = most common vascular lesion; self limiting

      • Biopsy

    • low-rate bleeding

      • Inflammatory bowel disease

      • Benign/malignant tumor

      • Mesenteric varices

  • Rx:

    • Intraarterial vasopressin infusion

      Prognosis:

      90% initial control rate; in 30% recurrent bleeding

    • Transcatheter embolization

      • Requires superselective catheterization using microcatheters + microembolic agents

      Cx:

      25% risk of bowel infarction + stricture

Gastrointestinal Bleeding in Infant

• Peptic ulcer

• Varices

• Ulcerated Meckel diverticulum

Gastrointestinal Bleeding in Child

• Meckel diverticulum

• Juvenile polyp

• Inflammatory bowel disease

• Clotting disorder

• Arteriovenous malformation

Intramural Hemorrhage

• VASCULITIS

  • Henoch-Sch nlein purpura

• TRAUMA

• COAGULATION DEFECT

  • Anticoagulant therapy

  • Thrombocytopenia

  • Disseminated intravascular coagulation

• DISEASES WITH COAGULATION DEFECT

  • Hemophilia

  • Leukemia, lymphoma

  • Multiple myeloma

  • Metastatic carcinoma

  • Idiopathic thrombocytopenic purpura

• ISCHEMIA (often fatal)

  • abdominal pain

  • melena

Site:

submucosal/intramural/mesenteric

• stacked coin / picket fence appearance of mucosal folds (due to symmetric infiltration of submucosal blood)

• thumbprinting = rounded polypoid filling defect (due to focal accumulation of hematoma in bowel wall)

• separation + uncoiling of bowel loops

• narrowing of lumen + localized filling defects (asymmetric hematoma)

• no spasm/irritability

• mechanical obstruction + proximal distension of loops

Prognosis:

resolution within 2 6 weeks

GI Abnormalities In Chronic Renal Failure And Renal Transplantation

• @ Esophagus

  • Esophagitis: candida, CMV, herpes

P.754




• @ Stomach & duodenum

  • Gastritis

    • thickened gastric folds (38%)

    • edema + erosions

    • Cause:

      • imbalance of gastrin levels + gastric acid secretion due to

        • reduced removal of gastrin from kidney with loss of cortical mass

        • impaired acid feedback mechanism

        • hypochlorhydria

      • opportunistic infection (eg, CMV)

  • Gastric ulcer (3.5%)

  • Duodenal ulcer (2.4%)

  • Duodenitis (47%)

• @ Colon

  • More severely + frequently affected after renal transplantation

  • Progressive distention + pseudoobstruction

    Contributing factors:

    dehydration, alteration of diet, inactivity, nonabsorbable antacids, high-dose steroids

  • Ischemic colitis

    • primary disease responsible for end-stage renal disease (eg, diabetes, vasculitis)

    • trauma of renal transplantation

  • Diverticulitis

    Contributing factors:

    chronic obstipation, steroids, autonomic nervous dysfunction

  • Pseudomembranous colitis

  • Uremic colitis = nonspecific colitis

  • Spontaneous colonic perforation

    Cause:

    nonocclusive ischemia, diverticula, duodenal + gastric ulcers

• @ Pancreas

  • Pancreatitis

    Cause:

    hypercalcemia, steroids, infection, immunosuppressive agents, trauma

• @ General

  • GI hemorrhage

    Cause:

    gastritis, ulcers, colonic diverticula, ischemic bowel, infectious colitis, pseudomembranous colitis, nonspecific cecal ulceration

  • Bowel perforation (in 1 4% of transplant recipients)

  • Opportunistic infection

    Organism:

    Candida, herpes, CMV, Strongyloides

  • Malignancy

    • skin tumors

    • lymphoma

Enteropathy

Protein-Losing Enteropathy

• DISEASE WITH MUCOSAL ULCERATION

  • Carcinoma

  • Lymphoma

  • Inflammatory bowel disease

  • Peptic ulcer disease

• HYPERTROPHIED GASTRIC RUGAE

  • M n trier disease

• NONULCERATIVE MUCOSAL DISEASE

  • Celiac disease

  • Tropical sprue

  • Whipple disease

  • Allergic gastroenteropathy

  • Gastrocolic fistula

  • Villous adenoma of colon

• LYMPHATIC OBSTRUCTION

  • Intestinal lymphangiectasia

• HEART DISEASE

  • Constrictive pericarditis

  • Tricuspid insufficiency

Malabsorption

• = deficient absorption of any essential food materials within small bowel

• PRIMARY MALABSORPTION

  • = the digestive abnormality is the only abnormality present

  • Celiac disease = nontropical sprue

  • Tropical sprue

  • Disaccharidase deficiencies

• SECONDARY MALABSORPTION

  • = occurring during course of gastrointestinal disease

  • enteric

    • Whipple disease

    • Parasites: hookworm, Giardia, fish tapeworm

    • Mechanical defects: fistulas, blind loops, adhesions, volvulus, short circuits

    • Neurologic: diabetes, functional diarrhea

    • Inflammatory: enteritis (viral, bacterial, fungal, nonspecific)

    • Endocrine: Zollinger-Ellison syndrome

    • Drugs: neomycin, phenindione, cathartics

    • Collagen disease: scleroderma, lupus, polyarteritis

    • Lymphoma

    • Benign + malignant small bowel tumors

    • Vascular disease

    • CHF, agammaglobulinemia, amyloid, abetalipoproteinemia, intestinal lymphangiectasia

  • gastric

    • vagotomy, gastrectomy, pyloroplasty, gastric fistula (to jejunum, ileum, colon)

  • pancreatic

    • pancreatitis, pancreatectomy, pancreatic cancer, cystic fibrosis

  • hepatobiliary

    • intra- and extra-hepatic biliary obstruction, acute + chronic liver disease

Roentgenographic Signs in Malabsorption

• SMALL BOWEL WITH NORMAL FOLDS + FLUID

  • Maldigestion (deficiency of bile salt/pancreatic enzymes)

  • Gastric surgery

  • Alactasia

• SMALL BOWEL WITH NORMAL FOLDS + WET

  • Sprue

  • Dermatitis herpetiformis

P.755




• DILATED DRY SMALL BOWEL

  • Scleroderma

  • Dermatomyositis

  • Pseudoobstruction: no peristaltic activity

• DILATED WET SMALL BOWEL

  • Sprue

  • Obstruction

  • Blind loop

• THICKENED STRAIGHT FOLDS + DRY SMALL BOWEL

  • Amyloidosis (malabsorption is unusual)

  • Radiation

  • Ischemia

  • Lymphoma (rare)

  • Macroglobulinemia (rare)

• THICKENED STRAIGHT FOLDS + WET SMALL BOWEL

  • Zollinger-Ellison syndrome

  • Abetalipoproteinemia: rare inherited disease characterized by CNS damage, retinal abnormalities, steatorrhea, acanthocytosis

• THICKENED NODULAR IRREGULAR FOLDS + DRY SMALL BOWEL

  • Lymphoid hyperplasia

  • Lymphoma

  • Crohn disease

  • Whipple disease

  • Mastocytosis

• THICKENED NODULAR IRREGULAR FOLDS + WET SMALL BOWEL

  • Lymphangiectasia

  • Giardiasis

  • Whipple disease (rare)

Small Bowel Nodularity with Malabsorption

mnemonic:

What is His Main Aim? Lay Eggs, By God

• W hipple disease

• I ntestinal lymphangiectasia

• H istiocytosis

• M astocytosis

• A myloidosis

• L ymphoma, L ymph node hyperplasia

• E dema

• B lood

• G iardiasis

Abdominal Mass

Abdominal Mass in Neonate

• RENAL (55%)

  • Hydronephrosis (25%)

  • Multicystic dysplastic kidney (15%)

  • Polycystic kidney

  • Mesoblastic nephroma

  • Renal vein thrombosis

• GENITAL (15%)

  • Ovarian cyst

  • Hydrometrocolpos

• GASTROINTESTINAL (15%)

  • Duplication

  • Volvulus

  • Cystic meconium peritonitis

  • Mesenteric cyst

• NONRENAL RETROPERITONEAL (10%)

  • Adrenal hemorrhage

  • Neuroblastoma

  • Teratoma

• HEPATOBILIARY (5%)

  • Hemangioendothelioma

  • Choledochal cyst

  • Hydrops of gallbladder

Abdominal Mass in Infant &Child

• RENAL (55%)

  • Wilms tumor (22%)

  • Hydronephrosis (20%)

  • Cystic renal mass

  • Congenital anomaly

• NONRENAL RETROPERITONEAL (23%)

  • Neuroblastoma (21%)

  • Teratoma

• GASTROINTESTINAL (18%)

  • Appendiceal abscess (10%)

  • Hepatobiliary (6%)

• GENITAL (4%)

  • Ovarian cyst/teratoma

  • Hydrometrocolpos

Abnormal Intraabdominal Air

Abnormal Air Collection

• Abnormally located bowel

  • Chilaiditi syndrome (= colon interposed between liver and chest wall), inguinal hernia

• Pneumoperitoneum

• Retropneumoperitoneum

  • perforation of duodenum/rectum/ascending + descending colon, diverticulitis, ulcerative disease, endoscopic procedure

• Gas in bowel wall

  • gastric pneumatosis, phlegmonous gastritis, endoscopy, rupture of lung bulla

• Gas within abscess

  • located in subphrenic, renal, perirenal, hepatic, pancreatic space, lesser sac

• Gas in biliary system = pneumobilia

• Gas in portal venous system

Pneumoperitoneum

Cause:

• DISRUPTION OF WALL OF HOLLOW VISCUS

  • trauma

  • iatrogenic perforation

  • diseases of GI tract

    • Perforated gastric/duodenal ulcer

    • Perforated appendix

    • Ingested foreign-body perforation

    • Diverticulitis (ruptured Meckel diverticulum/sigmoid diverticulum, jejunal diverticulosis)

    • Necrotizing enterocolitis with perforation

    P.756

    
    

    • Inflammatory bowel disease (eg, toxic megacolon)

    • Obstruction (gas traversing intact mucosa): neoplasm, imperforate anus, Hirschsprung disease, meconium ileus

    • Ruptured pneumatosis cystoides intestinalis with balanced pneumoperitoneum (= free intraperitoneal air acts as tamponade of pneumatosis cysts thus maintaining a balance between intracystic air + pneumoperitoneum)

    • Idiopathic gastric perforation = spontaneous perforation in premature infants (congenital gastric muscular wall defect)

• THROUGH PERITONEAL SURFACE

  • transperitoneal manipulation

    • Abdominal needle biopsy/catheter placement

    • Mistaken thoracentesis/chest tube placement

    • Endoscopic biopsy

  • extension from chest

    • Dissection from pneumomediastinum (positive pressure breathing, rupture of bulla/bleb, chest surgery)

    • Bronchopleural fistula

  • rupture of urinary bladder

  • penetrating abdominal injury

• THROUGH FEMALE GENITAL TRACT

  • iatrogenic

    • Perforation of uterus/vagina

    • Culdocentesis

    • Rubin test = tubal patency test

    • Pelvic examination

  • spontaneous

    • Intercourse, orogenital insufflation

    • Douching

    • Knee-chest exercise, water skiing, horseback riding

• INTRAPERITONEAL

  • Gas-forming peritonitis

  • Rupture of abscess

Note

= asymptomatic spontaneous pneumoperitoneum without peritonitis

• air in lesser peritoneal sac

• gas in scrotum (through open processus vaginalis)

• Large collection of gas:

  • abdominal distension, no gastric air-fluid level

  • football sign = large pneumoperitoneum outlining entire abdominal cavity

  • double wall sign = Rigler sign = bas-relief sign

    • = air outlining the luminal + serosal surface of the bowel wall with patient in supine position (usually requires >1,000 mL of free intraperitoneal gas + intraperitoneal fluid)

    • [Leo Rigler (1896 1979), radiologist in Minneapolis, USA]

  • telltale triangle sign = triangular air pocket between 3 loops of bowel

  • depiction of diaphragmatic muscle slips = two or three 6 13-cm long and 8 10-mm wide arcuate soft-tissue bands directed vertically inferiorly + arching parallel to diaphragmatic dome superiorly

  • outline of ligaments of anterior inferior abdominal wall:

  • inverted V sign = outline of both lateral umbilical ligaments (containing inferior epigastric vessels)

  • outline of medial umbilical ligaments (obliterated umbilical arteries)

  • urachus sign = outline of middle umbilical ligament

• RUQ gas (best place to look for small collections):

  • single large area of hyperlucency over the liver

  • oblique linear area of hyperlucency outlining the posteroinferior margin of liver

  • doge's cap sign = triangular collection of gas in Morison pouch (posterior hepatorenal space)

  • outline of falciform ligament = long vertical line to the right of midline extending from ligamentum teres notch to umbilicus; most common structure outlined

  • ligamentum teres sign = air outlining fissure of ligamentum teres hepatis (= posterior free edge of falciform ligament) seen as vertically oriented sharply defined slitlike/oval area of hyperlucency between 10th and 12th rib within 2.5 4.0 cm of right vertebral border 2 7 mm wide and 6 20 mm long

  • ligamentum teres notch = inverted V-shaped area of hyperlucency along undersurface of liver

  • saddlebag/mustache/cupola sign = gas trapped below central tendon of diaphragm

  • parahepatic air = gas bubble lateral to right edge of liver

Iatrogenic Pneumoperitoneum

• Laparotomy/laparoscopy (58%)

  • absorbed in 1 24 days dependent on initial amount of air introduced and body habitus (80% in asthenic, 25% in obese patients)

  • After 3 days free air should be followed with suspicion!

• Leaking surgical anastomosis

• Peritoneal dialysis

• Feeding tube placement

• Endoscopic perforation

• Enema tip injury

• Use of gynecologic instruments

• Vigorous respiratory resuscitation

• Diagnostic pneumoperitoneum

Spontaneous Pneumoperitoneum

• Peptic perforation

• Ischemia

• Bowel obstruction

• Toxic megacolon

• Inflammation: appendicitis, tuberculosis, necrotizing enteroccolitis

Traumatic Pneumoperitoneum

• Blunt trauma

• Penetrating trauma:

  • Perforating foreign body (eg, thermometer injury to rectum, vaginal stimulator in rectum)

  • Compressor air directed toward anus

Miscellaneous Causes of Pneumoperitoneum

• Drugs: steroids, NSAID

• Pneumatosis coli/intestinalis

• Entry through female genital tract: douching, sexual intercourse, insufflation

P.757

Pseudopneumoperitoneum

• = process mimicking free air

• ABDOMINAL GAS

  • gastrointestinal gas

    • Pseudo-wall sign = apposition of gas-distended bowel loops

    • Chilaiditi syndrome

    • Diaphragmatic hernia

    • Diverticulum of esophagus/stomach/duodenum

  • extraintestinal gas

    • Retroperitoneal air

    • Subdiaphragmatic abscess

• CHEST

  • Pneumothorax

  • Empyema

  • Irregularity of diaphragm

• FAT

  • Subdiaphragmatic intraperitoneal fat

  • Interposition of omental fat between liver + diaphragm

Pneumoretroperitoneum

Cause:

• Traumatic rupture (usually duodenum)

• Perforation of duodenal ulcer

• Gas abscess of pancreas (usually extends into lesser sac)

• Urinary tract gas (trauma, infection)

• Dissected mediastinal air

• kidney outlined by gas

• outline of psoas margin gas streaks in muscle bundles

Pneumatosis Intestinalis

• = PNEUMATOSIS CYSTOIDES INTESTINALIS = BULLOUS EMPHYSEMA OF THE INTESTINE = INTESTINAL GAS CYSTS = PERITONEAL LYMPHOPNEUMATOSIS

• Cause:

  • Attributed to at least 58 causative factors!

  • BOWEL NECROSIS/GANGRENE

    • Most common + life-threatening cause!

    Pathogenesis:

    damage + disruption of mucosa with entry of gas-forming bacteria into bowel wall (cysts contain 50% hydrogen = evidence of bacterial origin)

    • necrotizing enterocolitis, ischemia + infarction (mesenteric thrombosis), neutropenic colitis, sepsis, volvulus, emphysematous gastritis, caustic ingestion

  • MUCOSAL DISRUPTION

    Pathogenesis:

    increased intestinal gas pressure leads to overdistension and dissection of gas into bowel wall

    • intestinal obstruction:

      • pyloric stenosis, annular pancreas, imperforate anus, Hirschsprung disease, meconium plug syndrome, obstructing neoplasm

    • intestinal trauma:

      • endoscopy biopsy, biliary stent perforation, sclerotherapy, bowel surgery, postoperative bowel anastomosis, penetrating/blunt abdominal trauma, trauma of child abuse, intracatheter jejunal feeding tube, barium enema

    • infection/inflammation:

      • peptic ulcer disease, intestinal parasites, tuberculosis, peritonitis, inflammatory bowel disease (Crohn disease, ulcerative colitis, pseudomembranous colitis), ruptured jejunal diverticula, Whipple disease, systemic amyloidosis

  • INCREASED MUCOSAL PERMEABILITY

    Pathogenesis:

    defects in lymphoid tissue of bowel wall allows bacterial gas to enter bowel wall

    • immunotherapy:

      • graft-versus-host disease, organ transplantation, bone marrow transplantation

    • others:

      • AIDS enterocolitides, steroid therapy, chemotherapy, radiation therapy, collagen vascular disease (scleroderma, systemic lupus erythematosus, periarteritis dermatomyositis), intestinal bypass enteropathy, diabetes mellitus

  • PULMONARY DISEASE

    Pathogenesis:	alveolar rupture with air dissecting interstitially along bronchovascular bundles to mediastinum + retroperitoneally along vascular supply of viscera
    Cause:	Chronic obstructive pulmonary disease (chronic bronchitis, emphysema, bullous disease of lung), asthma, cystic fibrosis, chest trauma (barotrauma from artificial ventilation, chest tube), increased intrathoracic pressure associated with retching + vomiting

  Path:	(a) microvesicular type = 10 100-mm cysts/bubbles within lamina propria (b) linear/curvilinear type = streaks of gas oriented parallel to bowel wall
  Location:	any part of GI tract; may be discontinuous with spread to distant sites along mesentery
  Site:	subserosa > submucosa > muscularis > mesentery; mesenteric side >> antimesenteric side

• radiolucent clusters of cysts along contour of bowel wall (best demonstrated on CT)

• segmental mucosal nodularity (DDx: polyposis)

• pneumoperitoneum/pneumoretroperitoneum (asymptomatic large pneumoperitoneum may persist for months/years)

• gas in mesenteric + portal vein

• Prognosis:

  • wide spectrum from innocuous to fatal; clinical outcome impossible to predict based on x-ray findings

  • Linear gas collections probably have a more severe connotation

  • Pneumatosis of the colon is likely clinically insignificant

  • Extent of pneumatosis is inversely related to severity of disease

Soap-bubble Appearance in Abdomen of Neonate

• Feces in infant fed by mouth

• Meconium ileus:

  • gas mixed with meconium, usually RLQ

P.758




• Meconium plug:

  • gas in and around plug, in distribution of colon

• Necrotizing enterocolitis: submucosal pneumatosis

• Atresia/severe stenosis: pneumatosis

• Hirschsprung disease:

  • impacted stool, sometimes pneumatosis

Abdominal Calcifications & Opacities

Opaque Material in Bowel

mnemonic:

CHIPS

• C hloral hydrate

• H eavy metals (lead)

• I ron

• P henothiazines

• S alicylates

Diffuse Abdominal Calcifications

• Cystadenoma of ovary

  • granular, sandlike psammomatous calcifications

• Pseudomyxoma peritonei

  • pseudomucinous adenoma of ovary

  • mucocele of appendix

• Undifferentiated abdominal malignancy

• Tuberculous peritonitis

  • mottled calcifications simulating residual barium

• Meconium peritonitis

• Oil granuloma

  • annular/plaquelike calcifications

Focal Alimentary Tract Calcifications

• ENTEROLITHS

  • Appendicolith: in 10 15% of acute appendicitis

  • Stone in Meckel diverticulum

  • Diverticular stone

  • Rectal stone

  • Proximal to partial obstruction (eg, tuberculosis, Crohn disease)

• MESENTERIC CALCIFICATIONS

  • Dystrophic calcification of omental fat deposits + appendices epiploicae (secondary to infarction/pancreatitis/TB)

  • Cysts: mesenteric cyst, hydatid cyst

  • Calcified mesenteric lipoma

• INGESTED FOREIGN BODIES

  • trapped in appendix, diverticula, proximal to stricture

  • 1. Calcified seeds + pits (bezoar)

  • 2. Birdshot

  • Location of intraluminal lodgement:

    • esophagus (68%), stomach (11.6%), small bowel (3.3%), colon (11.6%)

• TUMOR

  • Mucocele of appendix

    • crescent-shaped/circular calcification

  • Mucinous adenocarcinoma of stomach/colon

    • = COLLOID CARCINOMA

    • small mottled/punctate calcifications in primary site in regional lymph node metastases, adjacent omentum, metastatic liver foci

  • Gastric/esophageal leiomyoma: calcifies in 4%

  • Lipoma

Abdominal Wall Calcifications

• IN SOFT TISSUES

  • Hypercalcemic states

  • Idiopathic calcinosis

• IN MUSCLE

  • parasites:

    • Cysticercosis = Taenia solium

      • round/slightly elongated calcifications

    • Guinea worm = dracunculiasis

      • stringlike calcifications up to 12 cm long

  • injection sites

    • from quinine, bismuth, calcium gluconate, calcium penicillin

  • myositis ossificans

• IN SKIN

  • Soft-tissue nodules: papilloma, neurofibroma, melanoma, nevi

  • Scar:

    • linear density

  • Colostomy/ileostomy

  • Tattoo markings

Abdominal Vascular Calcifications

• ARTERIES

  • Atheromatous plaques

  • Arterial calcifications in diabetes mellitus

• VEINS

  • phleboliths = calcified thrombus, generally seen below interspinous line

  • Normal/varicose veins

  • Hemangioma

• LYMPH NODES

  • Histoplasmosis/tuberculosis

  • Chronic granulomatous disease

  • Residual lymphographic contrast

  • Silicosis

Abnormal Intraabdominal Fluid

Ascites

Cause:

• TRANSUDATE

  • Cirrhosis (75%): poor prognostic sign

  • Hypoproteinemia

  • CHF

  • Constrictive pericarditis

  • Chronic renal failure

  • Budd-Chiari syndrome

• EXUDATE

  • Carcinomatosis

  • Polyserositis

  • TB peritonitis

  • Pancreatitis

  • Meigs syndrome

• HEMORRHAGIC/CHYLOUS FLUID

• Early signs (accumulation in pelvis):

  • round central density in pelvis + ill-defined bladder top

  • thickening of peritoneal flank stripe

  P.759

  
  

  • space between properitoneal fat and gut >3 mm

• Late signs:

  • Hellmer sign = medial displacement of lateral liver margins

  • medial displacement of ascending + descending colon

  • obliteration of hepatic + splenic angles

  • bulging flanks

  • gray abdomen

  • floating centralized loops

  • separation of loops

High-density Ascites

• Tuberculosis: 20 45 HU; may be lower

• Ovarian tumor

• Appendiceal tumor

Neonatal Ascites

• GASTROINTESTINAL

  • perforation of hollow viscus

    • Meconium peritonitis

  • inflammatory lesions

    • Meckel diverticulum

    • Appendicitis

  • cyst rupture

    • Mesenteric cyst

    • Omental cyst

    • Choledochal cyst

  • bile leakage

    • Biliary obstruction

    • Biliary perforation

• PORTOHEPATIC

  • extrahepatic portal vein obstruction

    • Atresia of veins

    • Compression by mass

  • intrahepatic portal vein obstruction

    • Portal cirrhosis (neonatal hepatitis)

    • Biliary cirrhosis (biliary atresia)

• URINARY TRACT

  • Urine ascites (most common cause) from lower urinary tract obstruction + upper urinary tract rupture: posterior/anterior urethral valves, ureterovesical/ureteropelvic junction obstruction, renal/bladder rupture, anterior urethral diverticulum, bladder diverticula, neurogenic bladder, extrinsic bladder mass

• GENITAL

  • Ruptured ovarian cyst

  • Hydrometrocolpos

• HYDROPS FETALIS

  • Immune hydrops

  • Nonimmune hydrops (usually cardiac causes)

• MISCELLANEOUS

  • Chylous ascites

  • Lymphangiectasia

  • Congenital syphilis, trauma

  • Idiopathic

Chylous Ascites

IN ADULTS:	1. Inflammatory process	(35%)
	2. Tumor	(30%)
	3. Idiopathic	(23%)
	4. Trauma	(11%)
	5. Congenital	(1%)
IN CHILDREN:	1. Congenital	(39%)
	2. Inflammatory process	(15%)
	3. Trauma	(12%)
	4. Tumor	(3%)
	5. Idiopathic	(33%)

Fluid Collections

mnemonic:

BLUSCHINGS

• Biloma

• Lymphocele, Lymphangioma, Lymphoma (almost anechoic by US)

• Urinoma

• Seroma

• Cyst (pseudocyst, peritoneal inclusion cyst)

• Hematoma (aneurysm, AVM)

• Infection, Infestation (empyema, abscess, Echinococcus)

• Neoplasm (necrotic)

• GI tract (dilated loops, ileus, duplication)

• Serosa (ascites, pleural fluid, pericardial effusion)

Intraabdominal Cyst in Childhood

• Omental cyst (greater omentum/lesser sac, multilocular)

• Mesenteric cyst (between leaves of small bowel mesentery)

• Choledochal cyst

• Intestinal duplication

• Ovarian cyst

• Pancreatic pseudocyst

• Cystic renal tumor

• Abscess

• Meckel diverticulum (communicates with GI tract)

• Lymphangioma

• Mesenteric lymphoma

• Intramural tumor

Mechanical Intestinal Obstruction

• = occlusion/constriction of bowel lumen

Prevalence:

20% of acute abdominal admissions
80% small bowel obstruction
20% large bowel obstruction

Air Progression in Neonates

stomach	within minutes after birth
entire small bowel	within 3 hours
sigmoid colon	after 8 9 hours

Cause of Absent Gas in Neonate

• GI obstruction

• Mechanical ventilation in severe respiratory distress

• Continuous gastric suction

Cause of Delayed Passage of Gas in Neonate

• Traumatic delivery

• Septicemia

• Hypoglycemia

• Brain damage

Passage of Meconium

• NORMAL

  • in 94% within 24 hours

  P.760

  
  

  • in 99% within 48 hours

  exceptions:

  prematurity, severely asphyxiated term infants

• DELAYED PASSAGE

  • Hirschsprung disease

  • Ileal/jejunal atresia

  • Meconium ileus

  • Meconium plug syndrome

  • Colon atresia

  • Imperforate anus

Common Causes of Obstruction in Children

Time of presentation:

Nursery	Intestinal atresia, midgut volvulus, meconium ileus, Hirschsprung disease, small bowel atresia with meconium ileus, meconium plug syndrome, small left colon syndrome, imperforate anus, obstruction from duplication cyst
First 3 months	Hypertrophic pyloric stenosis, inguinal hernia, Hirschsprung disease, midgut volvulus
6 24 months	Ileocolic intussusception
Childhood	Appendicitis

Terminology:

• High obstruction = proximal to midileum

  • Rarely needs further radiologic evaluation

  • bilious vomiting (after first feeding)

  • abdominal distention

  • few dilated bowel loops

• Low obstruction = distal ileum/colon

  • More difficult to accurately localize

  • Requires contrast enema examination to diagnose microcolon, position of cecum, level of obstruction

  • abdominal distention + vomiting

  • failure to pass meconium

  • many dilated intestinal loops

Intestinal Obstruction in Neonate:

• abdominal distension

• vomiting

• failure to pass meconium

• Duodenal atresia (50%), stenosis (40%), web (10%)

• Midgut volvulus

• Jejunal/ileal atresia

• Meconium ileus

• Meconium plug syndrome

• Hirschsprung disease

• Necrotizing enterocolitis

NEONATAL OBSTRUCTION WITH MICROCOLON

• Ileal atresia

• Distal jejunal atresia

• Meconium ileus

NEONATAL OBSTRUCTION WITH NORMAL COLON

• Meconium plug

• Hirschsprung disease

Intestinal Obstruction in Infant & Child

• Hypertrophic pyloric stenosis

• Appendicitis

• Intussusception

Gastric Outlet Obstruction

• CONGENITAL LESION

  • Antral mucosal diaphragm = antral web

  • Gastric duplication: usually along greater curvature, abdominal mass in infancy

  • Hypertrophic pyloric stenosis

• INFLAMMATORY NARROWING

  • Peptic ulcer disease: cause in adults in 60 65%

  • Corrosive gastritis

  • Crohn disease, sarcoidosis, syphilis, tuberculosis

• MALIGNANT NARROWING

  • Antral carcinoma: cause in adults in 30 35%

  • Scirrhous carcinoma of pyloric channel

• OTHERS

  • Prolapsed antral polyp/mucosa

  • Bezoar

  • Gastric volvulus

  • Postoperative stomal edema

• Abdominal plain film:

  • large smoothly marginated homogeneous mass displacing transverse colon + small bowel inferiorly

  • one/two air-fluid levels

Duodenal Obstruction

Cause:

• CONGENITAL

  • Annular pancreas

  • Peritoneal bands = Ladd bands

  • Aberrant vessel

• INFLAMMATORY NARROWING

  • Chronic duodenal ulcer scar

  • Acute pancreatitis: phlegmon, abscess, pseudocyst

  • Acute cholecystitis: perforated gallstone

• INTRAMURAL HEMATOMA

  • Blunt trauma (accident, child abuse)

  • Anticoagulant therapy

  • Blood dyscrasia

• TUMORAL NARROWING

  • Primary duodenal tumors

  • Tumor invasion from pancreas, right kidney, lymph node enlargement

• EXTRINSIC COMPRESSION

  • Aortic aneurysm

  • Pseudoaneurysm

• OTHERS

  • Superior mesenteric artery syndrome from extensive burns, body cast, rapid weight loss, prolonged bed rest

  • Bezoar (in gastrectomized patient)

mnemonic:

VA BADD TU BADD

child	adult
Volvulus	Tumor
Atresia	Ulcer
Bands	Bands
Annular pancreas	Annular pancreas
Duplication	Duplication
Diverticulum	Diverticulum

P.761

• Abdominal plain film:

  • double-bubble sign = air-fluid levels in stomach + duodenum

  • frequently normal due to absence of gas from vomiting

Jejunal and Ileal Obstruction

• = SMALL BOWEL OBSTRUCTION (SBO)

Frequency:	accounts for 20% of all surgical admissions
Mortality:	5.5% (dictum: Never let the sun rise or set on small-bowel obstruction )

Cause:

• CONGENITAL

  • Jejunal atresia

  • Ileal atresia/stenosis

  • Enteric duplication: located on antimesenteric side, mostly in ileum

  • Midgut volvulus from arrest in rotation + fixation of small bowel during fetal life

  • Mesenteric cyst from meconium peritonitis:located on mesenteric side

  • Meckel diverticulum

• EXTRINSIC BOWEL LESION

  • Fibrous adhesions (50 75%) from previous surgery (80%), peritonitis (15%), congenital/uncertain cause (5%)

  • Hernia (10%): internal/external

  • Volvulus

  • Masses: extrinsic neoplasm (most commonly advanced peritoneal carcinomatosis), abscess, aneurysm, hematoma, endometriosis

• LUMINAL OCCLUSION

  • swallowed:

    • Foreign body: in children; mentally disturbed/disabled patients

    • Bezoar

    • Gallstone

    • Inspissated milk

    • Bolus of Ascaris lumbricoides

  • after birth:

    • Meconium ileus:

      • microcolon in cystic fibrosis

    • Meconium ileus equivalent

  • other:

    • Intussusception

    • Tumor (rare): eg, lipoma

• INTRINSIC BOWEL WALL LESION

  • neoplasm

    • Adenocarcinoma

    • Carcinoid tumor

    • Lymphoma

    • Gastrointestinal stromal tumor

  • inflammatory lesion

    • Crohn disease

    • Tuberculous enteritis

    • Eosinophilic gastroenteritis

    • Parasitic disease

  • vascular insufficiency

    • Ischemia (arterial/venous occlusion)

    • Radiation enteropathy

  • intramural hemorrhage

    • Blunt trauma

    • Henoch-Sch nlein purpura

    • Anticoagulants

  • strictures

    • Surgical anastomosis

    • Irradiation

    • Potassium chloride tablets

    • Massive deposition of amyloid

Plain abdominal radiograph (50 66% sensitive):

• candy cane appearance in erect position = >3 distended small bowel loops >3 cm with gas-fluid levels (>3 5 hours after onset of obstruction)

• disparity in size between obstructed loops and contiguous small bowel loops of normal caliber beyond site of obstruction

• small bowel positioned in center of abdomen

• little/no gas + stool in colon with complete mechanical obstruction after 12 24 hours

• stretch sign = erectile valvulae conniventes completely encircle bowel lumen

• stepladder appearance in low obstruction (the greater the number of dilated bowel loops, the more distal the site of obstruction)

• string-of-beads indicate peristaltic hyperactivity to overcome mechanical obstruction

• hyperactive peristalsis/aperistalsis = fatigued small bowel

• snake head appearance = active peristalsis forms bulbous head of barium column in an attempt to overcome obstruction

• barium appears in colon >12 hours

CAVE:

little/no gas in small bowel from fluid-distended loops may lead one to overlook obstruction

Location of obstruction:

• valvulae conniventes high + frequent = jejunum

• valvulae conniventes sparse/absent = ileum

Plain abdominal radiographic categories:

• Normal

  • = absence of small intestinal gas/gas within 3 4 variably shaped loops <2.5 cm in diameter

• Mild small bowel stasis

  • = single/multiple loops of 2.5 3 cm in diameter with 3 air-fluid levels

• Probable SBO pattern

  • = dilated multiple gas-/fluid-filled loops with air-fluid levels + moderate amount of colonic gas

• Definite SBO pattern

  • = clearly disproportionate gaseous/fluid distension of small bowel relative to colon

UGI:

• snake head appearance = active peristalsis forms bulbous head of barium column in an attempt to overcome obstruction

• barium appears in colon >12 hours

Enteroclysis for adhesive obstruction:

• abrupt change in caliber of bowel with normal caliber/collapsed bowel distal to obstruction

• stretched folds of normal pattern

P.762




• angulated + fixed bowel segment

Enteroclysis categories of SBO (Shrake):

• low-grade partial SBO

  • = sufficient flow of contrast material through point of obstruction so that fold pattern beyond obstruction is readily defined

• high-grade partial SBO

  • = stasis + delay in arrival of contrast so that contrast material is diluted in distended prestenotic loop with minimal contrast in postobstructive loop leading to difficulty in defining fold pattern after transition point

• complete SBO

  • = no passage of contrast material 3 24 hours after start of examination

CT (66% accurate, 78% specific, 63% sensitive, [81% sensitive for high-grade obstruction, 48% sensitive for low-grade partial obstruction]):

• small bowel dilatation >2.5 cm (not reliable to distinguish from adynamic ileus):

  • small bowel feces sign = gas bubbles mixed with particulate matter immediately proximal to obstruction (DDx: cystic fibrosis)

• discrepant caliber at transition zone from dilated to nondilated bowel:

  • level of obstruction best determined by relative lengths of dilated versus collapsed bowel

  • passage of contrast material through transition zone indicates incomplete obstruction

• triangular beak immediately beyond dilated segment = point of transition

DDx:

adynamic ileus (distension of entire small bowel)

US:

• small bowel loops dilated >3 cm

• length of dilated segment >10 cm

• increased peristalsis of dilated segment (may become paralytic in prolonged obstruction)

• colon collapsed

Strangulated Obstruction:

• = impaired circulation/ischemia of obstructed segment

Prevalence:	5 10 42% of patients with SBO
At risk:	patients with acute complete/high-grade SBO; risk increases over time

TRIAD:

• closed-loop obstruction of the involved segment (majority of cases)

• mechanical obstruction proximal to the involved segment

• venous congestion of the involved loop

CT (63 100% detection rate):

• slight circumferential thickening of bowel wall:

  • increased wall attenuation

  • target/halo sign

• serrated beaklike narrowing at site of obstruction (32 100% specific) = closed loop with regional mesenteric vascular engorgement + bowel wall thickening at the obstructed segment

• unusual course of mesenteric vasculature

• vascular compromise of affected bowel:

  • poor/no enhancement of bowel wall (100% SPECIFIC)

  • delayed prolonged enhancement of bowel wall

  • mesenteric haziness due to edema (95% specific)

  • diffuse engorgement of mesenteric vasculature

  • localized mesenteric fluid/hemorrhage

• large amount of ascites

• pneumatosis intestinalis

• gas in portal vein

Prognosis:

• 20 37% mortality rate (compared with 5 8% for a recently reduced simple obstruction) due to delay in diagnosis: 8% for surgery performed in <36 hours, 25% mortality for surgery performed in >36 hours

CLOSED-LOOP OBSTRUCTION

• = obstruction at two points along the course of the bowel at a single site usually with involvement of mesentery

Pathophysiology:

impaired venous arterial flow

• Most common cause of strangulation!

Cause:

adhesion (75%), incarcerated hernia

• fixation of bowel loop = no change in position:

  • coffee bean sign = gas-filled loop

  • pseudotumor = fluid-filled loop

  • U- or C-shaped dilated bowel loop on CT

• increasing intraluminal fluid

• beak sign = point of obstruction on CT/UGI

• whirl sign = twisting of bowel + mesentery on CT:

  • stretched engorged mesenteric vessels converging toward site of obstruction/torsion delayed enhancement

Cx:

volvulus

Acquired Small Bowel Obstruction in Childhood

mnemonic:

AAIMM

• Adhesions

• Appendicitis

• Intussusception

• Incarcerated hernia

• Malrotation

• Meckel diverticulum

Small Bowel Obstruction in Adulthood

mnemonic:

SHAVIT

• Stone (gallstone ileus)

• Hernia (21%)

• Adhesion (49%)

• Volvulus

• Intussusception

• Tumor (16%)

SBO IN VIRGIN ABDOMEN OF ADULTHOOD

• Bowel ischemia including ischemic stricture

• Primary small bowel neoplasm

• Metastatic small bowel neoplasm

• Extrinsic abdominal mass

• Internal/abdominal wall hernia

• Crohn disease

Colonic Obstruction

Incidence:

25% of all intestinal obstructions

P.763

Cause:

• NEONATAL COLONIC OBSTRUCTION

  • Meconium plug syndrome

  • Colonic atresia

  • Anorectal malformation: rectal atresia, imperforate anus

  • Hirschsprung disease

  • functional colonic immaturity (especially in premies + infants of mothers treated with magnesium or high doses of sedatives/opiates, children with septicemia, hypothyroidism, hypoglycemia, diabetic mothers)

    • small left colon syndrome

    • meconium plug syndrome

• LUMINAL OBTURATION

  • Fecal impaction

    • bubbly pattern of large mass of stool

  • Fecaloma

  • Gallstone (in sigmoid narrowed by diverticulitis)

  • Intussusception

• BOWEL WALL LESION

  • malignant (60 70% of obstructions) predominantly in sigmoid

  • inflammatory

    • Crohn disease

    • Ulcerative colitis

    • Mesenteric ischemia

    • Sigmoid diverticulitis (15%)

      • stenotic segment >6 cm

    • Acute pancreatitis

  • infectious:

    • infectious granulomatous process

      • Actinomycosis

      • Tuberculosis

      • Lymphogranuloma venereum

    • parasitic disease

      • Amebiasis

      • Schistosomiasis

  • wall hematoma:

    • blunt trauma, coagulopathy

• EXTRINSIC

  • mass impression

    • Endometriosis

    • Large tumor mass: prostate, bladder, uterus, tubes, ovaries

    • Pelvic abscess

    • Hugely distended bladder

    • Mesenteritis

    • Poorly formed colostomy

  • severe constriction

    • Volvulus (3rd most common cause): sigmoid colon, cecum, transverse colon, compound volvulus (= ileosigmoid knot)

    • Hernia: transverse colon in diaphragmatic hernia, sigmoid colon in left inguinal hernia

    • Adhesion

Abdominal plain-film patterns:

• dilated colon only = competent ileocecal valve

• dilated small bowel (25%) = incompetent ileocecal valve

• dilated colon + dilated small bowel = ileocecal valve obstruction secondary to cecal overdistension

• gas-fluid levels distal to hepatic flexure (fluid is normal in cecum + ascending colon); sign not valid with diarrhea/saline catharsis/enema

• cecum most dilated portion (in 75% of cases); critical at 10 cm diameter (high probability for impending perforation)

• The lower the obstruction, the more proximal the distension!

BE:

Emergency barium enema of unprepared colon in suspected obstruction!
Contraindicated in toxic megacolon, pneumatosis intestinalis, portal vein gas, extraluminal gas

Ileus

• [ileus = stasis/inability to push fluid along (term does not distinguish between mechanical and nonmechanical causes)]

• = ADYNAMIC/PARALYTIC/NONOBSTRUCTIVE ILEUS

• = derangement impairing proper distal propulsion of intestinal contents

Cause:

• in neonate:

  • Hyperbilirubinemia

  • Intracranial hemorrhage

  • Aspiration pneumonia

  • Necrotizing enterocolitis

  • Aganglionosis

• in child/adult:

  • Postoperative ileus

    • usually resolves by 4th postoperative day

  • Visceral pain: obstructing ureteral stone, common bile duct stone, twisted ovarian cyst, blunt abdominal/chest trauma

  • Intraabdominal inflammation/infection: peritonitis, appendicitis, cholecystitis, pancreatitis, salpingitis, abdominal abscess, hemolytic-uremic syndrome, gastroenteritis

  • Ischemic bowel disease

  • Anticholinergic drugs: atropine, propantheline, morphine + derivatives, tricyclic antidepressants, dilantin, phenothiazines, hexamethonium bromide

  • Neuromuscular disorder: diabetes, hypothyroidism, porphyria, lead poisoning, uremia, hypokalemia, amyloidosis, urticaria, sprue, scleroderma, Chagas disease, vagotomy, myotonic dystrophy, CNS trauma, paraplegia, quadriplegia

  • Systemic disease: septic/hypovolemic shock, urticaria

  • Chest disease: lower lobe pneumonia, pleuritis, myocardial infarction, acute pericarditis, congestive heart failure

  • Retroperitoneal disease: hemorrhage (spine trauma), abscess

mnemonic:

Remember the P's

• Pancreatitis

• Pendicitis

• Peptic ulcer

• Perforation

• Peritonitis

• Pneumonia

P.764




• Porphyria

• Postoperative

• Potassium paucity

• Pregnancy

• Pyelonephritis

• intestinal sounds decreased/absent

• abdominal distension

• large + small bowel gastric distension

• decreased small bowel distension on serial films

• delayed but free passage of contrast material

Rx:

not amenable to surgical correction

Localized Ileus

• = isolated distended loop of small/large bowel

• = SENTINEL LOOP

Often associated with:

adjacent acute inflammatory process

Etiology:

1. Acute pancreatitis:	duodenum, jejunum, transverse colon
2. Acute cholecystitis:	hepatic flexure of colon
3. Acute appendicitis:	terminal ileum, cecum
4. Acute diverticulitis:	descending colon
5. Acute ureteral colic:	GI tract along course of ureter

Intestinal Pseudoobstruction

• TRANSIENT PSEUDOOBSTRUCTION

  • Electrolyte imbalance

  • Renal failure

  • Congestive heart failure

• ACUTE COLONIC PSEUDOOBSTRUCTION (Ogilvie syndrome)

• CHRONIC PSEUDOOBSTRUCTION

  • Scleroderma

  • Amyloidosis

• IDIOPATHIC PSEUDOOBSTRUCTION

  • Chronic intestinal pseudoobstruction syndrome

  • Megacystis-microcolon-intestinal-hypoperistalsis syndrome

Esophagus

Esophageal Contractions

• Esophageal motor activity needs to be evaluated in recumbent position without influence of gravity!

• PERISTALTIC EVENT = coordinated contractions of esophagus

• PERISTALTIC SEQUENCE = aboral stripping wave clearing esophagus

Primary Esophageal Peristalsis

• = orderly peristaltic sequence with progressive aboral stripping traversing entire esophagus with complete clearance of barium; centrally mediated (medulla) swallow reflex via glossopharyngeal + vagal nerve; initiated by swallowing

• rapid wave of inhibition followed by slower wave of contraction

• Normal peristaltic sequence will be interrupted by repetitive swallowing before peristaltic sequence is complete!

Secondary Esophageal Peristalsis

• = local peristaltic wave identical to primary peristalsis but elicited through esophageal distension = sensorimotor stretch reflex

• Esophageal motility can be evaluated with barium injection through nasoesophageal tube despite patient's inability to swallow!

Tertiary Esophageal Contractions

• = nonpropulsive esophageal motor event characterized by disordered up-and-down movement of bolus without clearing of esophagus

Cause:

• Presbyesophagus

• Diffuse esophageal spasm

• Hyperactive achalasia

• Neuromuscular disease:

  • @ diabetes mellitus, parkinsonism, amyotrophic lateral sclerosis, multiple sclerosis, thyrotoxic myopathy, myotonic dystrophy

• Obstruction of cardia:

  • neoplasm, distal esophageal stricture, benign lesion, S/P repair of hiatal hernia

  • Tertiary activity does not necessarily imply a significant motility disturbance!

Age:

in 5 10% of normal adults during 4th 6th decade

• nonsegmental = partial luminal indentation

  Location:

  in lower 2/3 of esophagus

  • spontaneous repetitive nonpropulsive contraction

  • yo-yo motion of barium

  • corkscrew appearance = scalloped configuration of barium column

  • rosary bead / shish kebab configuration = compartmentalization of barium column

  • no lumen-obliterating contractions

• segmental = luminal obliteration (rare)

  • curling = erratic segmental contractions

  • rosary-bead appearance

Abnormal Esophageal Peristalsis

• PRIMARY MOTILITY DISORDERS

  • Achalasia

  • Diffuse esophageal spasm

    • severe intermittent pain while swallowing

    • compartmentalization of esophagus by numerous tertiary contractions

    Dx:

    extremely high pressures on manometry

  • Presbyesophagus

  • Chalasia

  • Congenital TE fistula

  • Intestinal pseudoobstruction

• SECONDARY MOTILITY DISORDERS

  • connective tissue disease

    • Scleroderma

    • SLE

    • Rheumatoid arthritis

    • Polymyositis

    • Dermatomyositis

    • Muscular dystrophy

  P.765

  
  

  • chemical/physical injury

    • Reflux/peptic esophagitis

    • S/P vagotomy

    • Caustic esophagitis

    • Radiotherapy

  • infection

    fungal:	candidiasis
    parasitic:	Chagas disease
    bacterial:	TB, diphtheria
    viral:	herpes simplex

  • metabolic disease

    • Diabetes mellitus

    • Amyloidosis

    • Alcoholism

    • Electrolyte disturbances

  • endocrine disease

    • Myxedema

    • Thyrotoxicosis

  • neoplasm

  • drug-related: atropine, propantheline, curare

  • muscle disease

    • Myotonic dystrophy

    • Muscular dystrophy

    • Oculopharyngeal dystrophy

    • Myasthenia gravis (disturbed motility only in striated muscle of upper 1/3 of esophagus)

      • persistent collection of barium in upper third of esophagus

      • findings reversed by cholinesterase inhibitor edrophonium (Tensilon )

  • neurologic disease

    • Parkinsonism

    • Multiple sclerosis

    • CNS neoplasm

    • Amyotrophic lateral sclerosis

    • Bulbar poliomyelitis

    • Cerebrovascular disease

    • Huntington chorea

    • Ganglioneuromatosis

    • Wilson disease

    • Friedreich ataxia

    • Familial dysautonomia (Riley-Day)

    • Stiff-man syndrome

Diffuse Esophageal Dilatation

• = ACHALASIA PATTERN = MEGAESOPHAGUS

• ESOPHAGEAL MOTILITY DISORDER

  • Idiopathic achalasia

  • Chagas disease: patients commonly from South America; often associated with megacolon + cardiomegaly

  • Postvagotomy syndrome

  • Scleroderma

  • Systemic lupus erythematosus

  • Presbyesophagus

  • Ehlers-Danlos syndrome

  • Diabetic/alcoholic neuropathy

  • Anticholinergic drugs

  • Idiopathic intestinal pseudoobstruction

    • = degeneration of innervation

  • Amyloidosis: associated with macroglossia, thickened small bowel folds

  • Esophagitis

• DISTAL OBSTRUCTION

  • Infiltrating lesion of distal esophagus/gastric cardia (eg, carcinoma) = pseudoachalasia

  • Benign stricture

  • Extrinsic compression

  mnemonic:

  MA'S TACO in a SHell

  • M uscular disorder (eg, myasthenia gravis)

  • A chalasia

  • S cleroderma

  • T rypanosomiasis (Chagas disease)

  • A myloidosis

  • C arcinoma

  • O bstruction

  • S tricture (lye, potassium, tetracycline)

  • H iatal hernia

Air Esophagogram

• Normal variant

• Scleroderma

• Distal obstruction: tumor, stricture, achalasia

• Thoracic surgery

• Mediastinal inflammatory disease

• S/P total laryngectomy (esophageal speech)

• Endotracheal intubation + PEEP

Abnormal Esophageal Folds

• TRANSVERSE FOLDS

  • Feline esophagus

    • frequently seen with gastroesophageal reflux; normally found in cats

      • transient contraction of longitudinally oriented muscularis mucosae

  • Fixed transverse folds

    • due to scarring from reflux esophagitis

    • stepladder appearance in distal esophagus

• LONGITUDINAL FOLDS

  normal:

  1 2 mm wide, best seen in collapsed esophagus

  • >3 mm with submucosal edema/inflammation

  • Gastroesophageal reflux

  • Opportunistic infection

  • Caustic ingestion

  • Irradiation

DDx:

(1) Varices
tortuous/serpentine folds that can be effaced by esophageal distension
(2) Varicoid carcinoma
fixed rigid folds with abrupt demarcation due to submucosal spread

Esophageal Inflammation

• CONTACT INJURY

  • reflux related

    • Peptic ulcer disease

    • Barrett esophagus

    • Scleroderma (patulous LES)

    • Nasogastric intubation

  P.766

  
  

  • caustic

    • Foreign body

    • Corrosives

  • thermic

    • habitual ingestion of excessively hot meals/liquids

• RADIATION INJURY

• INFECTION

  • Candidiasis

  • Herpes simplex virus/CMV

  • Diphtheria

• SYSTEMIC DISEASE

  • dermatologic disorders

    • blistering of skin + mucous membranes in response to minor trauma

    • Epidermolysis bullosa dystrophica

      Histo:

      intraepidermal bullae

    • Benign mucous membrane pemphigoid

      • = rare disease of unknown cause

      Histo:	subepidermal bullae without acantholysis
      Age:	4th decade; M < F

      • esophageal lesions (in 2 13%) most frequent at sites of relative stasis (aortic knob, carina, GE junction):

        • thin smooth webs arising from anterior aspect

        • stenoses of variable length

    • Pemphigus vulgaris

  • others:

    • Crohn disease

    • Graft-versus-host disease

    • Beh et disease

    • Eosinophilic gastroenteritis

Esophageal Ulcer

• PEPTIC

  • Reflux esophagitis: scleroderma

  • Barrett esophagus

  • Crohn disease

  • Dermatologic disorders: benign mucous membrane pemphigoid, epidermolysis bullosa dystrophica, Beh et disease

• INFECTIOUS

  • Herpes

  • Cytomegalovirus

• CONTACT INJURY/EXTERNAL INJURY

  • Corrosives: alkali, strictures in 50%

  • Alcohol-induced esophagitis

  • Drug-induced esophagitis

  • Radiotherapy: smooth stricture >4,500 rads

    • shallow/deep ulcers conforming to radiation portal

  • Nasogastric tube

    • elongated stricture in middle + distal 1/3

  • Endoscopic sclerotherapy

• MALIGNANT

  • Esophageal carcinoma

Location:

• @ Upper esophagus

  • Barrett ulcer in islets of gastric mucosa

• @ Midesophagus

  • Herpes esophagitis

  • CMV esophagitis

  • Drug-induced esophagitis

• @ Distal esophagus

  • Reflux esophagitis

  • CMV esophagitis

• DDx:

  • Sacculation

    • = outpouching in distal esophagus due to asymmetric scarring in reflux esophagitis

  • Esophageal intramural pseudodiverticula

  • Artifact

    • tiny precipitates of barium

    • transient mucosal crinkling in inadequate distension

    • irregular Z-line

Small Esophageal Ulcer (<1 cm)

• Herpes simplex virus type I

• Drug-induced

• Reflux esophagitis

• Beh et syndrome

• Benign mucous membrane pemphigoid

• Acute radiation change

Large Esophageal Ulcer (>1 cm)

• Cytomegalovirus

• Human immunodeficiency virus

• Carcinoma

• Drug-induced

• Barrett esophagus

• Sclerotherapy for varices

Double-barrel esophagus

• Dissecting intramural hematoma from emetogenic injury

• Mallory-Weiss tear trauma, esophagoscopy (in 0.25%), bougienage (in 0.5%), ingestion of foreign bodies, spontaneous (bleeding diathesis)

• Intramural abscess

• Intraluminal diverticulum

• Esophageal duplication (if communication with esophageal lumen present)

Esophageal Diverticulum

• Zenker diverticulum (pharyngoesophageal)

• Interbronchial diverticulum

  • = traction diverticulum

  • = response to pull from fibrous adhesions following lymph node infection (TB), contains all 3 esophageal layers

    Location:

    usually on right anterolateral wall of interbronchial segment

  • calcified mediastinal nodes

• Interaorticobronchial diverticulum

  • = thoracic pulsion diverticulum

  Location:

  on left anterolateral wall between inferior border of aortic arch + upper margin of left main bronchus

• Epiphrenic diverticulum (rare)

  Location:

  usually on lateral esophageal wall, right > left, in distal 10 cm

  • often associated with hiatus hernia

P.767




• Intramural esophageal pseudodiverticulosis

  • outpouching from mucosal glands

Tracheobronchoesophageal Fistula

• CONGENITAL

  • Congenital tracheoesophageal fistula

• MALIGNANCY (in 60%)

  • Lung cancer

  • Metastases to mediastinal lymph nodes

  • Esophageal cancer

    • In 5 10% of patients with advanced esophageal cancer

  • Radiation treatment of mediastinal malignancy

• TRAUMATIC

  • Instrumentation (esophagoscopy, bougienage, pneumatic dilatation)

  • Blunt ( crush injury )/penetrating chest trauma

  • Surgery

  • Foreign-body perforation

  • Corrosives

  • Postemetic rupture = Boerhaave syndrome

• INFECTIOUS/INFLAMMATORY

  • TB, syphilis, histoplasmosis, actinomycosis, Crohn disease

  • Perforated diverticulum

  • Pulmonary sequestration/cyst

Long Smooth Esophageal Narrowing

• Congenital esophageal stenosis

  • at junction between middle + distal third

  • weblike/tubular stenosis of 1 cm in length

• Surgical repair of esophageal atresia

  • interruption of primary peristaltic wave at anastomosis

  • secondary contractions may produce retrograde flow with aspiration

  • impaction of food

• Caustic burns = alkaline burns

• Alendronate (= inhibitor of osteoclastic activity)

• Gastric acid: reflux, hyperemesis gravidarum

• Intubation: reflux + compromise of circulation

• Radiotherapy for esophageal carcinoma; tumor of lung, breast, or thymus; lymphoma; metastases to mediastinal lymph nodes

  Onset of stricture:	usually 4 8 months post Rx
  Dose:	3,000 5,000 rad

• Postinfectious: moniliasis (rare)

Lower Esophageal Narrowing

mnemonic:

SPADE

• S cleroderma

• P resbyesophagus

• A chalasia; A nticholinergics

• D iffuse esophageal spasm

• E sophagitis

Focal Esophageal Narrowing

• Esophageal web

  • = 1 2-mm thick (vertical length) area of complete/incomplete circumferential narrowing

• Esophageal ring

  • = 5 10-mm thick (vertical length) area of complete/incomplete circumferential narrowing

• Esophageal stricture

  • = >10 mm in vertical length

mnemonic:

LETTERS MC

• Lye ingestion

• Esophagitis

• Tumor

• Tube (prolonged nasogastric intubation)

• Epidermolysis bullosa

• Radiation

• Surgery, S cleroderma

• Moniliasis

• Congenital

Midesophageal Stricture

• Barrett esophagus

• Radiation injury

• Caustic esophagitis

• Primary carcinoma: squamous cell carcinoma

• Metastatic cancer (from subcarinal nodes/left mainstem bronchus)

• Drug-induced stricture (esp. potassium chloride)

• Esophageal intramural pseudodiverticulosis

• Dermatologic disorder: benign mucous membrane pemphigoid, epidermolysis bullosa

• Graft-versus-host disease

Long Distal Esophageal Stricture

• SEVERE ACID EXPOSURE

  • Nasogastric intubation

  • Zollinger-Ellison syndrome

  • Alkaline reflux esophagitis

• INFLAMMATION

  • Crohn disease

Short Distal Esophageal Stricture

• Reflux esophagitis

• Carcinoma (adenocarcinoma)

• Crohn disease

• Schatzki ring

Esophageal Filling Defect

• BENIGN TUMORS

  • <1% of all esophageal tumors

  • Submucosal tumor (75%)

    • = nonepithelial, intramural

    • Leiomyoma (50% of all benign tumors)

      • Most common submucosal mass in esophagus

    • Granular cell myoblastoma

    • Lipoma, fibroma, lipoma, fibrolipoma, myxofibroma, hamartoma, hemangioma, lymphangioma, neurofibroma, schwannoma,

      • primary wave stops at level of tumor

      • proximal esophageal dilatation + hypotonicity

      • rigid esophageal wall at site of tumoral implant

      • disorganized/altered/effaced mucosal folds around defect

      • tumor shadow on tangential view extending beyond esophageal margin

  P.768

  
  

  • Mucosal tumor (25%) = epithelial, intraluminal

    • Squamous papilloma

      • = most common benign mucosal tumor; rarely multiple (esophageal papillomatosis)

      • small sessile slightly lobulated polyp

    • Fibrovascular polyp

      Path:	fibrovascular + adipose tissue
      Location:	cervical esophagus near cricopharyngeus

      • giant sausage-shaped intraluminal mass

      Cx:

      regurgitation into larynx causes sudden death

    • Inflammatory esophagogastric polyp

      • = sentinel polyp = bulbous tip of thickened gastric fold

      Cause:	sequelae of chronic reflux esophagitis
      Prognosis:	no malignant potential

    • Adenoma

      • = originates in Barrett mucosa

      • sessile/pedunculated polyp

      Cx:

      malignant degeneration

    • Glycogen acanthosis

• MALIGNANT TUMORS

  • Esophageal cancer

    • squamous/varicoid squamous cell carcinoma

    • adenocarcinoma

    • spindle cell carcinoma: leiomyosarcoma, carcinosarcoma, pseudosarcoma

  • Carcinoma of cardia (gastric cancer)

  • Metastases: malignant melanoma, lymphoma (<1% of gastrointestinal lymphomas), stomach, lung, breast

• VASCULAR

  • Varices

• INFECTION/INFLAMMATION

  • Candida/herpes esophagitis

  • Drug-induced inflammatory reaction

• CONGENITAL/NORMAL VARIANT

  • Prolapsed gastric folds

  • Esophageal duplication cyst (0.5 2.5% of all esophageal tumors)

• FOREIGN BODIES

  • Retained food particles (chicken bone, fish bone, pins, coins, small toys, meat)

  • Undissolved effervescent crystals

  • Air bubbles

Esophageal Mucosal Nodules/Plaques

plaque	= discrete irregular/ovoid elevation barely protruding above mucosal surface
nodule	= small more rounded elevation

• Candida esophagitis

• Reflux esophagitis (early stage)

• Barrett esophagus

• Glycogen acanthosis

• Superficial spreading carcinoma

• Artifacts (undissolved effervescent agent, air bubbles, debris)

Extrinsic Esophageal Impression

Cervical Causes of Esophageal Impression

• OSSEOUS LESIONS

  • Anterior marginal osteophyte/DISH

  • Anterior disk herniation

  • Cervical trauma + hematoma

  • Osteomyelitis

  • Bone neoplasm

• ESOPHAGEAL WALL LESIONS

  • muscle

    • Cricopharyngeus

    • Esophageal web

  • vessel

    • Pharyngeal venous plexus

    • Lymph node enlargement

• ENDOCRINE ORGANS

  • Thyroid/parathyroid enlargement (benign/malignant)

  • Fibrotic traction after thyroidectomy

• Retropharyngeal/mediastinal abscess

Thoracic Causes of Esophageal Impression

• NORMAL INDENTATIONS

  • aortic arch, left mainstem bronchus, left inferior pulmonary vein, diaphragmatic hiatus

• ABNORMAL VASCULATURE

  • right-sided aortic arch, cervical aortic arch, aortic unfolding, aortic tortuosity, aortic aneurysm, double aortic arch ( reverse S ), coarctation of aorta ( reverse figure 3 ), aberrant right subclavian artery

  • = arteria lusoria (semilunar/bayonet-shaped imprint upon posterior wall of esophagus), aberrant left pulmonary artery (between trachea + esophagus), anomalous pulmonary venous return (anterior), persistent truncus arteriosus (posterior)

• CARDIAC CAUSES

  • enlargement of chambers

    • left atrial/left ventricular enlargement: mitral disease (esophageal displacement backward + to the right)

  • pericardial masses

    • pericardial tumor/cyst/effusion

• MEDIASTINAL CAUSES

  • mediastinal tumor, lymphadenopathy (metastatic, tuberculous), inflammation, cyst

• PULMONARY CAUSES

  • pulmonary tumor, bronchogenic cyst, atypical pulmonary fibrosis (retraction)

• ESOPHAGEAL ABNORMALITIES

  • Esophageal diverticulum

  • Paraesophageal hernia

  • Esophageal duplication

Stomach

Gastric Tumor

Classification based on Biologic Behavior

• MALIGNANT (10 15%)

  • Adenocarcinoma (>95%)

  • Lymphoma, mucosa-associated lymphoid tissue (MALT)

  P.769

  
  

  • Sarcoma: leiomyosarcoma, Kaposi sarcoma

  • Carcinoid tumor

  • Metastasis

    • hematogenous: malignant melanoma, breast cancer

      • one/more submucosal masses

      • target/bull's-eye lesion if centrally ulcerated

      • giant cavitated lesion

      • linitis plastica (usually in breast cancer)

    • direct invasion

      • Barrett cancer: gastric fundus

      • Pancreatic cancer: stomach/duodenal sweep

      • Colonic cancer: greater gastric curvature

      • Omental cake: greater gastric curvature

• BENIGN (85 90%)

  • epithelial/mucosal tumor (50%)

    • Hyperplastic polyp

    • Adenomatous polyp

    • Brunner gland hyperplasia

  • mesenchymal tumor (50%)

    • Leiomyoma

    • Ectopic pancreatic rest

Mesenchymal Tumors of GI Tract

• SOMATIC SOFT TISSUE TUMOR

  • smooth muscle tumor

    • True leiomyoma

    • True leiomyosarcoma

  • neural tumor

    • 4% of all benign gastric tumors

    • Schwannoma

    • Neurofibroma

    • Plexosarcoma

  • lipocytic tumor

    • Lipoma (2 3% of all benign gastric tumors)

    • Liposarcoma

  • vascular/perivascular tissue

    • 2% of all benign gastric tumors

    • Glomus tumor (most common)

    • Hemangioma

    • Lymphangioma

• GASTROINTESTINAL STROMAL TUMOR

Calcified Gastric Tumor

• Mucinous adenocarcinoma: miliary/punctate

• Stromal tumors: amorphous calcifications

• Hemangioma: clusters of phleboliths

Congenital Gastric Obstruction

• COMPLETE OBSTRUCTION

  • Gastric atresia

    Frequency:	<1% of all GI obstructions
    May be associated with:	epidermolysis bullosa
    Site:	antrum + pylorus

    • regurgitation of bile-free vomitus within first few hours after birth

    • single bubble appearance of air in stomach

    • membranous mucosal diaphragm

  • Congenital peritoneal bands

  • Annular pancreatic tissue

• PARTIAL GASTRIC OUTLET OBSTRUCTION

  • cyclic transient postprandial vomiting

  • Incomplete prepyloric diaphragm

  • Antral stenosis

  • Aberrant pancreatic tissue in gastric antrum

  • Antral duplication cyst

Widened Retrogastric Space

• PANCREATIC MASSES (most common cause)

  • Acute + chronic pancreatitis

  • Pancreatic pseudocyst

  • Pancreatic cystadenoma + carcinoma

• OTHER RETROPERITONEAL MASSES

  • Sarcoma

  • Renal tumor, adrenal tumor

  • Lymph node enlargement

  • Abscess, hematoma

• GASTRIC MASSES

  • Leiomyoma, leiomyosarcoma

• OTHERS

  • Aortic aneurysm

  • Choledochal cyst

  • Obesity

  • Postsurgical disruptions + adhesions

  • Ascites

  • Gross hepatomegaly + enlarged caudate lobe

  • Hernia involving omentum

Gas within Stomach Wall

• NONINFECTIOUS

  • Interstitial gastric emphysema

    • = gas accumulation in submucosa/subserosa/or both

    Cause:

    air from an extrinsic source

    • obstructive (due to raised intragastric pressure):

      • gastric outlet obstruction, volvulus, overinflation during gastroscopy, profuse severe vomiting

    • pulmonary (due to rupture + dissection of subpleural blebs in bullous emphysema along esophageal wall/mediastinum): pulmonary emphysema

    • traumatic (due to mucosal trauma):

      • instrumentation of stomach, recent gastroduodenal surgery, endoscopy (1.6%)

    • benign clinical course with spontaneous resolution

    • linear lucency conforming to contour of a thinwalled distended stomach

  • Cystic pneumatosis

    • = PNEUMATOSIS CYSTOIDES INTESTINALIS

    Cause:

    similar to interstitial gastric emphysema

    • little/no gastrointestinal symptoms

    • multiple 1 2-mm gas-filled cysts in wall of stomach and intestines

• INFECTIOUS

  • Emphysematous gastritis

  predisposing:

  corrosive gastritis, acid ingestion, severe necrotizing gastroenteritis, gastric ulcer disease with intramural perforation, gastric carcinoma, volvulus, gastric infarction

P.770

Gastric Atony

• = gastric retention in the absence of mechanical obstruction

Pathophysiology:

reflex paralysis

• abdominal distension

• vascular collapse (decreased venous return)

• vomiting

• large stomach filled with air + fluid (up to 7,500 mL)

• retention of barium

• absent/diminished peristaltic activity

• patulous pylorus

• frequently dilated duodenum

DDx:

gastric volvulus, pyloric stenosis

Acute Gastric Atony

• (may develop within 24 48 hours)

• Acute gastric dilatation: secondary to decreased arterial perfusion (ischemia, congestive heart failure) in old patients, usually fatal

• Postsurgical atony, ureteral catheterization

• Immobilization: body cast, paraplegia, postoperative state

• Abdominal trauma: especially back injury

• Severe pain: renal/biliary colic, migraine headaches, severe burns

• Infection: peritonitis, pancreatitis, appendicitis, subphrenic abscess, septicemia

Chronic Gastric Atony

• Neurologic abnormalities: brain tumor, bulbar poliomyelitis, vagotomy, tabes

• Muscular abnormalities: scleroderma, muscular dystrophy

• Drug-induced atony: atropine, morphine, heroin, ganglionic blocking agents

• Electrolyte imbalance: diabetic ketoacidosis, hypercalcemia, hypocalcemia, hypokalemia, hepatic coma, uremia, myxedema

• Diabetes mellitus = gastroparesis diabeticorum (0.08% incidence)

• Emotional distress

• Lead poisoning

• Porphyria

Narrowing of Stomach

• = linitis plastica type of stenosis

• MALIGNANCY

  • Scirrhous gastric carcinoma (involving portion/all of stomach)

  • Hodgkin lymphoma, NHL

  • Metastatic involvement (carcinoma of breast, pancreatic carcinoma, colonic carcinoma)

• INFLAMMATION

  • Chronic gastric ulcer disease with intense spasm

  • Pseudo-Billroth-I pattern of Crohn disease

  • Sarcoidosis

    • polypoid appearance, pyloric hypertrophy

    • gastric ulcers, duodenal deformity

  • Eosinophilic gastritis

  • Polyarteritis nodosa

  • Stenosing antral gastritis/hypertrophic pyloric stenosis

• INFECTION

  • Tertiary stage of syphilis

    • absent mucosal folds + peristalsis

    • no change over years

  • Tuberculosis (rare)

    • hyperplastic nodules/ulcerative lesion/annular lesion

    • pyloric obstruction, may cross into duodenum

  • Histoplasmosis

  • Actinomycosis

  • Strongyloidiasis

  • Phlegmonous gastritis

  • Toxoplasmosis

• TRAUMA

  • Corrosive gastritis

  • Radiation injury

  • Gastric freezing

  • Hepatic arterial chemotherapy infusion

• OTHERS

  • Perigastric adhesions (normal mucosa, no interval change, normal peristalsis)

  • Amyloidosis

  • Pseudolymphoma

  • Exogastric mass (hepatomegaly, pancreatic pseudocyst)

mnemonic:

SLIMRAGE

• Scirrhous carcinoma of stomach

• Lymphoma

• Infiltration from adjacent neoplasm

• Metastasis (breast carcinoma)

• Radiation therapy

• Acids (corrosive ingestion)

• Granulomatous disease (TB, sarcoidosis, Crohn)

• Eosinophilic gastroenteritis

Antral Narrowing

mnemonic:

SPICER

• Sarcoidosis, Syphilis

• Peptic ulcer disease

• Infection (tuberculosis, chronic granulomatous disease of childhood)

• Cancer (linitis plastica), Crohn disease, Caustic ingestion

• Eosinophilic gastritis

• Radiation

Antral Pad Sign

• = extrinsic impression of the posteroinferior wall of antrum

• Pancreatic cancer in head/body

• Pancreatitis

• Pancreatic pseudocyst

• Normal/distended gallbladder (patient in RAO position)

Intramural-Extramucosal Lesions of Stomach

• sharply delineated marginal/contour defect

• stretched folds over intact mucosa

• acute angle at margins

• may ulcerate centrally

• may become pedunculated and acquire polypoid appearance over years

P.771

• NEOPLASTIC

  1. Leiomyoma	(48%)
  2. Neurogenic tumors	(14%)
  3. Heterotopic pancreas	(12%)
  4. Fibrous tumor	(11%)
  5. Lipoma	(7%)
  6. Hemangioma	(7%)
  7. Glomus tumor	(rare)
  8. Carcinoid
  9. Metastatic tumor

• INFLAMMATION/INFECTION

  • Granuloma

    • Foreign-body granuloma

    • Sarcoidosis

    • Crohn disease

    • Tuberculosis

    • Histoplasmosis

  • Eosinophilic gastritis

  • Tertiary syphilis: infiltrative/ulcerative/tumorous type

  • Echinococcal cyst

• PANCREATIC ABNORMALITIES

  • Ectopic pancreas

  • Annular pancreas

  • Pancreatic pseudocyst

• DEPOSITS

  • Amyloid

  • Endometriosis

  • Localized hematoma

• OTHERS

  • Varices (ie, fundal)

  • Duplications (4% of all GI tract duplications)

Gastric Filling Defects

• INTRINSIC WALL LESIONS

  • benign (most common)

    • Polyps: hyperplastic, adenomatous, villous, hamartomatous (Peutz-Jeghers syndrome, Cowden disease)

    • Leiomyoma

    • Granulomatous lesions

      • Eosinophilic granuloma

      • Crohn disease

      • Tuberculosis

      • Sarcoidosis

    • Pseudolymphoma = benign reactive proliferation of lymphoid tissue

    • Extramedullary hematopoiesis

    • Ectopic pancreas

    • Gastric duplication cyst

    • Intramural hematoma

    • Esophagogastric herniation

  • malignant

    • Gastric carcinoma, lymphoma

    • Gastric sarcoma: leiomyosarcoma, liposarcoma, leiomyoblastoma

    • Gastric metastases: melanoma, breast, pancreas, colon

• EXTRINSIC IMPRESSIONS ON STOMACH

  • in 70% nonneoplastic (extrinsic pseudotumors in 20%)

  • normal organs: organomegaly, tortuous aorta, heart, cardiac aneurysm

  • benign masses:

    • cysts of pancreas, liver, spleen, adrenal, kidney; gastric duplication, postoperative deformity (eg, Nissen fundoplication)

  • malignant masses: enlarged celiac nodes

  • inflammatory lesion:

    • left subphrenic abscess/hematoma

    • lateral displacement: enlarged liver, aortic aneurysm, enlarged celiac nodes

    • medial displacement: splenomegaly, mass in colonic splenic flexure, cardiomegaly, subphrenic abscess

• INTRALUMINAL GASTRIC MASSES

  • Bezoar

  • Foreign bodies: food, pills, blood clot, gallstone

• TUMORS OF ADJACENT ORGANS

  • Pancreatic carcinoma + cystadenoma

  • Liver carcinoma

  • Carcinoma of gallbladder

  • Colonic carcinoma

  • Renal carcinoma

  • Adrenal carcinoma

  • Lymph node involvement

• THICKENED GASTRIC FOLDS

Filling Defect of Gastric Remnant

• IATROGENIC

  • surgical deformity/plication defect, suture granuloma

• INFLAMMATORY

  • bile reflux gastritis, hyperplastic polyps

• INTUSSUSCEPTION

  • Jejunogastric intussusception

    • (efferent loop in 75%, afferent loop in 25%)

    • (a) acute form: high intestinal obstruction, left hypochondriac mass, hematemesis

    • (b) chronic/intermittent form: may be self-reducing

    • coiled spring appearance of gastric filling defect

  • Gastrojejunal/gastroduodenal mucosal prolapse

    • often asymptomatic

    • bleeding partial obstruction

• NEOPLASTIC

  • Gastric stump carcinoma: >5 years after resection for benign disease; 15% within 10 years; 20% after 20 years

  • Recurrent carcinoma (10%) secondary to incomplete removal of gastric cancer

  • Malignancy at anastomosis (incomplete resection)

• INTRALUMINAL MATTER: bezoar

  mnemonic:

  PUBLICS

  • Polyp (hyperplastic polyp due to bile reflux)

  • Ulcer (anastomotic)

  • Bezoar, Blind loop syndrome

  • Loop (afferent loop syndrome)

  • Intussusception at gastrojejunostomy

  • Cancer (recurrent, residual, de novo)

  • Surgical deformity, Suture granuloma

P.772

Thickened Gastric Folds

• INFLAMMATION/INFECTION

  • Inflammatory gastritis:

    • alcoholic, hypertrophic, antral, corrosive, postirradiation, gastric cooling

  • Crohn disease

  • Sarcoidosis

  • Infectious gastritis:

    • bacterial invasion, bacterial toxins from botulism, diphtheria, dysentery, typhoid fever, anisakiasis, TB, syphilis

  • Pseudolymphoma

• MALIGNANCY

  • Lymphoma

  • Gastric carcinoma

• INFILTRATIVE PROCESS

  • Eosinophilic gastritis

  • Amyloidosis

• PANCREATIC DISEASE

  • Pancreatitis

  • Direct extension from pancreatic carcinoma

• OTHERS

  • Zollinger-Ellison syndrome

  • M n trier disease

  • Gastric varices

  mnemonic:

  ZEAL VOLUMES C^3MP³

  • Zollinger-Ellison syndrome

  • Amyloidosis

  • Lymphoid hyperplasia

  • Varices

  • Operative defect

  • Lymphoma

  • Ulcer disease (peptic)

  • M n trier disease

  • Eosinophilic gastroenteritis

  • Syphilis

  • Crohn disease, Carcinoma, Corrosive gastritis

  • Pancreatitis, Pancreatic carcinoma,

  • Postradiation gastritis

Bull's-eye Lesions

• PRIMARY NEOPLASMS

  • Leiomyoma, leiomyosarcoma

  • Lymphoma

  • Carcinoid

  • Primary carcinoma

• HEMATOGENOUS METASTASES

  • Malignant melanoma

    • usually spares large bowel

  • Breast cancer (15%)

    • scirrhous appearance in stomach

  • Cancer of lung

  • Renal cell carcinoma

  • Kaposi sarcoma

  • Bladder carcinoma

• ECTOPIC PANCREAS

  • in duodenum/stomach

• EOSINOPHILIC GRANULOMA

  • most frequently in stomach

Complications of Postoperative Stomach

• Filling defect of gastric remnant

• Retained gastric antrum

• Dumping syndrome

• Afferent loop syndrome

• Stomal obstruction

  • temporary reversible: edema of suture line, abscess/hematoma, potassium deficiency, inadequate electrolyte replacement, hypoproteinemia, hypoacidity

  • late mechanical: stomal ulcer (75%)

  mnemonic:

  LOBULATING

• Leaks (early)

• Obstruction (early)

• Bezoar

• Ulcer (especially marginal)

• Loop (afferent loop syndrome)

• Anemia (macrocytic secondary to decreased intrinsic factor)

• Tumor (? increased incidence)

• Intussusception

• Not feeling well after meals (dumping syndrome)

• Gastritis (bile reflux)

Lesions Involving Stomach and Duodenum = Transpyloric Disease

• Lymphoma: in up to 40% of patients with lymphoma

• Gastric carcinoma: in 5 25%, but 50 more common than lymphoma

• Peptic ulcer disease

• Tuberculosis: in 10% of gastric TB

• Crohn disease: pseudo-Billroth-I pattern

• Strongyloidiasis

• Eosinophilic gastroenteritis

Duodenum

Congenital Duodenal Obstruction

• bile-stained vomiting delayed until after first feeding and increasing progressively

• double bubble sign

• Duodenal atresia/severe stenosis

• Annular pancreas

• Midgut volvulus

• Duodenal web

• Ladd bands

• Preduodenal portal vein

• Duodenal duplication cyst

Extrinsic Pressure Effect on Duodenum

• BILE DUCTS

  • normal impression, dilated CBD, choledochal cyst

• GALLBLADDER

  • normal impression, gallbladder hydrops, Courvoisier phenomenon, gallbladder carcinoma, pericholecystic abscess

• LIVER

  • hepatomegaly, hypertrophied caudate lobe, anomalous hepatic lobe, hepatic cyst, hepatic tumor

• RIGHT KIDNEY

  • bifid collecting system, hydronephrosis, multiple renal cysts, polycystic kidney disease, hypernephroma

• RIGHT ADRENAL

  • adrenal carcinoma, enlargement in Addison disease

• COLON

  • duodenocolic apposition due to anomalous peritoneal fixation, carcinoma of hepatic flexure

• VESSELS

  • lymphadenopathy, duodenal varices, dilated arterial collaterals, aortic aneurysm, intramural/mesenteric hematoma

P.773

Gastric Surgical Procedures

Widened Duodenal Sweep

• NORMAL VARIANT

• PANCREATIC LESION

  • Acute pancreatitis

  • Chronic pancreatitis

  • Pancreatic pseudocyst

  • Pancreatic carcinoma

  • Metastasis to pancreas

  • Pancreatic cystadenoma

• VASCULAR LESION

  • Lymph node enlargement: lymphoma, metastasis, inflammation

  • Cystic lymphangioma of the mesentery

• RETROPERITONEAL MASS

  • Aortic aneurysm

  • Choledochal cyst

Thickened Duodenal Folds

• INFLAMMATION

  • within bowel wall:

    • peptic ulcer disease, Zollinger-Ellison syndrome, regional enteritis, lymphoid hyperplasia, uremia

  • surrounding bowel wall:

    • pancreatitis, cholecystitis

• INFECTION

  • giardiasis, TB, strongyloidiasis, celiac disease

P.774




• NEOPLASIA

  • lymphoma, metastases to peripancreatic nodes

• DIFFUSE INFILTRATIVE DISORDER

  • Whipple disease, amyloidosis, mastocytosis, eosinophilic enteritis, intestinal lymphangiectasia

• VASCULAR DISORDER

  • duodenal varices, mesenteric arterial collaterals, intramural hemorrhage (trauma, Sch nlein-Henoch purpura), chronic duodenal congestion (congestive heart failure, portal venous hypertension); lymphangiectasia

• HYPOPROTEINEMIA

  • nephrotic syndrome, M n trier disease, protein-losing enteropathy

• GLANDULAR ENLARGEMENT

  • Brunner gland hyperplasia, cystic fibrosis

mnemonic:

BAD HELP

• Brunner gland hyperplasia

• Amyloidosis

• Duodenitis (Z-E syndrome, peptic)

• Hemorrhage

• Edema, Ectopic pancreas

• Lymphoma

• Pancreatitis, Parasites

Duodenal Filling Defect

• EXTRINSIC

  • gallbladder impression, CBD impression, gas-filled diverticulum

• INTRINSIC TO WALL

  • benign neoplastic mass

    • Adenoma

    • Leiomyoma

    • Lipoma

    • Hamartoma (Peutz-Jeghers syndrome)

    • Prolapsed antral polyp

    • Brunner gland adenoma

    • Villous adenoma

    • Islet cell tumor

    • Gangliocytic paraganglioma

  • malignant neoplastic mass

    • Carcinoid tumor

    • Adenocarcinoma

    • Ampullary carcinoma

    • Lymphoma

    • Sarcoma

    • Metastasis (stomach, pancreas, gallbladder, colon, kidney, melanoma)

    • Retroperitoneal lymph node involvement

  • nonneoplastic mass

    • Papilla of Vater

    • Choledochocele

    • Duplication cyst

    • Pancreatic pseudocyst

    • Duodenal varix

    • Mesenteric artery collaterals

    • Intramural hematoma

    • Adjacent abscess, stitch abscess

    • Ectopic pancreas, heterotopic gastric mucosa

    • Prolapsed antral mucosa

    • Brunner gland hyperplasia

    • Benign lymphoid hyperplasia

• INTRALUMINAL

  • Blood clot

  • Foreign body: fruit pit, gallstone, feeding tube

Duodenal Tumor

Benign Duodenal Tumors

• Leiomyoma (27%)

• Adenomatous polyp (21%)

• Lipoma (21%)

• Brunner gland adenoma (17%)

• Angiomatous tumor (6%)

• Ectopic pancreas (2%)

• Duodenal cyst (2%)

• Neurofibroma (2%)

• Hamartoma (2%)

Malignant Duodenal Tumors

• Adenocarcinoma (73%)

  Location:	40% in duodenum, most often in 2nd + 3rd portion = periampullary neoplasm (a) suprapapillary: apt to cause obstruction + bleeding (b) peripapillary: extrahepatic jaundice (c) intrapapillary: GI bleeding
  Predisposed:	Gardner syndrome, celiac disease
  May be associated with:	Peutz-Jeghers syndrome annular/polypoid/ulcerative
  Metastases:	regional lymph nodes (2/3)
  DDx:	(1) Primary bile duct carcinoma (2) Ampullary carcinoma

• Leiomyosarcoma (14%)

  • most often beyond 1st portion of duodenum

    • up to 20 cm in size

    • frequently ulcerated exophytic mass

• Carcinoid (11%)

• Lymphoma (2%)

  • marked wall thickening

  • bulky periduodenal lymphadenopathy

Enlargement of Papilla of Vater

[Abraham Vater (1684 1751), anatomist in Wittenberg, Germany]

• Normal variant

  • identified in 60% of UGI series; atypical location in 3rd portion of duodenum in 8%; 1.5 cm in diameter in 1% of normals

• Papillary edema

  • Impacted stone

  • Pancreatitis (Poppel sign)

  • Acute duodenal ulcer disease

  • Papillitis

• Perivaterian neoplasms

  • = tumor mass + lymphatic obstruction

  • 1. Adenocarcinoma

  • 2. Adenomatous polyp (premalignant lesion)

    • irregular surface + erosions

• Lesions simulating enlarged papilla

  • Benign spindle cell tumor

  • Ectopic pancreatic tissue

P.775

Duodenal Narrowing

• DEVELOPMENTAL ANOMALIES

  • Duodenal atresia

  • Congenital web/duodenal diaphragm

  • Intraluminal diverticulum

  • Duodenal duplication cyst

  • Annular pancreas

  • Midgut volvulus, peritoneal bands (Ladd bands)

• INTRINSIC DISORDERS

  • inflammation/infection

    • Postbulbar ulcer

    • Crohn disease

    • Sprue

    • Tuberculosis

    • Strongyloidiasis

  • tumor

    • duodenal/ampullary malignancy

• DISEASE IN ADJACENT STRUCTURES

  • Pancreatitis, pseudocyst, pancreatic carcinoma

  • Cholecystitis

  • Contiguous abscess

  • Metastases to pancreaticoduodenal nodes (lymphoma, lung cancer, breast cancer)

• TRAUMA

  • Duodenal rupture

  • Intramural hematoma

• VASCULAR

  • Superior mesenteric artery syndrome

  • Aorticoduodenal fistula

  • Preduodenal portal vein (anterior to descending duodenum)

Dilated Duodenum

Megaduodenum	= marked dilatation of entire C-loop
Megabulbus	= dilatation of duodenal bulb only

• VASCULAR COMPRESSION

  • superior mesenteric artery syndrome, abdominal aortic aneurysm, aorticoduodenal fistula

• PRIMARY DUODENAL ATONY

  • scleroderma, dermatomyositis, SLE

  • Chagas disease, aganglionosis, neuropathy, surgical/chemical vagotomy

  • focal ileus: pancreatitis, cholecystitis, peptic ulcer disease, trauma

  • altered emotional status, chronic idiopathic intestinal pseudoobstruction

• INFLAMMATORY/NEOPLASTIC INDURATION OF MESENTERIC ROOT

  • Crohn disease, tuberculous enteritis, pancreatitis, peptic ulcer disease, strongyloidiasis, metastatic disease

• FLUID DISTENSION

  • celiac disease, Zollinger-Ellison syndrome

Postbulbar Ulceration

• Benign postbulbar peptic ulcer

  • medial aspect of upper 2nd portion

  • incisura pointing to ulcer

  • occasionally barium reflux into common bile duct

  • ring stricture

  • stress- and drug-induced ulcers heal without deformity

• Zollinger-Ellison syndrome

  • multiple ulcers distal to duodenal bulb

  • thickening of folds + hypersecretion

• Leiomyoma

• Malignant tumors:

  • primaries

    • adenocarcinoma, lymphoma, sarcoma

  • contiguous spread

    • pancreas, colon, kidney, gallbladder

  • hematogenous spread

    • melanoma, Kaposi sarcoma

  • lymphogenic spread

    • metastases to periduodenal lymph nodes

• Granulomatous disease: Crohn disease, TB

• Aorticoduodenal fistula

• Mimickers: ectopic pancreas, diverticulum

Small Bowel

Anatomic Predilection for Intestinal Involvement

@ proximal jejunum	diverticulosis, giardiasis, adenocarcinoma, Whipple disease, Z-E syndrome, celiac disease
@ distal ileum	Crohn disease, TB, infectious enteritis, lymphoma, carcinoid, metastases
@ mesenteric border	diverticulosis, Crohn disease, mesenteric hematoma, intraperitoneal spread of tumor
@ antimesenteric border	Meckel diverticulum, sacculations in scleroderma, hematogenous metastases

Increased Fluid within Small Bowel

• Ingestion

• Resection/removal of stomach

• Small-bowel obstruction

• Enteritis

• Malabsorption: celiac disease, Whipple disease

• Peritoneal carcinomatosis

Small Bowel Diverticula

• TRUE DIVERTICULA

  • Duodenal diverticula

    • Racemose diverticula: bizarre, lobulated

    • Giant diverticula

    • Intraluminal diverticula: result of congenital web/diaphragm

  • Jejunal diverticulosis

  • Meckel diverticulum

• PSEUDODIVERTICULA

  • Scleroderma

  • Crohn disease

  • Lymphoma

  • Mesenteric ischemia

  • Communicating ileal duplication

  • Giant duodenal ulcer

P.776

Small Bowel Ulcer

Aphthous Ulcers of Small Bowel

• INFECTION

  • Yersinia enterocolitis (25%)

  • Salmonellosis

  • Tuberculosis

  • Rickettsiosis

• INFLAMMATION

  • Crohn disease (22%)

  • Beh et syndrome

  • Reiter syndrome

  • Ankylosing spondylitis

Large Nonstenotic Ulcers of Small Bowel

• Primary nonspecific ulcer 47% incidence

• Yersiniosis 33%

• Crohn disease 30%

• Tuberculosis 18%

• Salmonellosis/shigellosis 7%

• Meckel diverticulum 5%

Multiple Small Bowel Ulcers

• DRUGS

  • Potassium tablets

  • Steroids

  • Nonsteroidal antiinflammatory drugs

• INFECTION/INFLAMMATION

  • Bacillary dysentery

  • Ischemic enteritis

  • Ulcerative jejunoileitis as complication of celiac disease

• TUMOR

  • Neoplasms

  • Intestinal lymphoma

Cavitary Small Bowel Lesion

• PRIMARY TUMOR

  • Lymphoma (exoenteric form)

  • Leiomyosarcoma (exoenteric form)

  • Primary adenocarcinoma

• METASTASIS

  • Malignant melanoma

  • Lung cancer

• INFLAMMATION

  • Diverticulitis with abscess (Meckel, jejunal)

  • Communicating duplication cyst

Separation of Bowel Loops

• INFILTRATION OF BOWEL WALL/MESENTERY

  • inflammation/infection

    • Crohn disease

    • TB

    • Radiation injury

    • Retractile mesenteritis

    • Intraperitoneal abscess

  • deposits

    • Intestinal hemorrhage/mesenteric vascular occlusion

    • Whipple disease

    • Amyloidosis

  • tumor

    • Carcinoid tumor: local release of serotonin responsible for muscular thickening + fibroplastic proliferation = desmoplastic reaction

    • Primary carcinoma of small bowel (unusual presentation)

    • Lymphoma

    • Neurofibromatosis

• ASCITES/INTRAPERITONEAL BLEEDING

  • hepatic cirrhosis (75%), peritonitis, peritoneal carcinomatosis, congestive heart failure, constrictive pericarditis, primary/metastatic lymphatic disease

• EXTRINSIC MASS

  • Intraperitoneal spread of tumor: peritoneal mesothelioma, mesenteric tumors (fibroma, lipoma, fibrosarcoma, leiomyosarcoma, malignant mesenteric lymphoid tumor, metastases)

  • Interloop abscesses/loculated fluid collection

  • Endometriosis

  • Retractile mesenteritis (fibrosis, fatty infiltration, panniculitis)

  • Mesenteric fat deposits

  • Fibrofatty proliferation: Crohn disease, mesenteric panniculitis

Normal Small Bowel Folds & Diarrhea

• Pancreatic insufficiency

• Lactase deficiency

• Lymphoma/pseudolymphoma

Dilated Small Bowel & Normal Folds

mnemonic:

SOS

• Sprue

• Obstruction

• Scleroderma

• EXCESSIVE FLUID

  • mechanical obstruction

    • due to adhesion, hernia, neoplasm

    • string-of-beads sign = air bubbles between mucosal folds in a fluid-filled small bowel

    • pseudotumor sign = closed-loop obstruction

  • malabsorption syndromes

    • Celiac disease, tropical + nontropical sprue

    • Lactase deficiency

• BOWEL WALL PARALYSIS

  • = functional ileus = adynamic ileus

  • 1. Surgical vagotomy

  • 2. Chemical vagotomy from drug effects: atropine-like substances, morphine, L-dopa, glucagon

  • 3. Chagas disease

  • 4. Metabolic: hypokalemia, diabetes

  • 5. Intrinsic + extrinsic intraabdominal inflammation

  • 6. Chronic idiopathic pseudoobstruction

• VASCULAR COMPROMISE

  • Mesenteric ischemia (atherosclerosis)

  • Acute radiation enteritis

  • Amyloidosis

  • SLE

• BOWEL WALL DESTRUCTION

  • Lymphoma

  P.777

  
  

  • Scleroderma (smooth muscle atrophy)

  • Dermatomyositis

Abnormal Small Bowel Folds

Abnormal Folds + Increased Intraluminal Fluid

• Malabsorption syndrome

• Crohn disease, infectious enteritis

• Parasitic infestation/giardiasis

• Ischemia proximal to an obstruction

• Zollinger-Ellison syndrome

• Lymphangiectasia, mesenteric lymphadenopathy

Thickened Folds of Stomach & Small Bowel

• Lymphoma

• Crohn disease

• Eosinophilic gastroenteritis

• Zollinger-Ellison syndrome

• M n trier disease

• Cirrhosis = gastric varices + hypoproteinemia

• Amyloidosis

• Whipple disease

• Systemic sclerosis

Thickened Smooth Folds Dilatation

• EDEMA

  • hypoproteinemia

    • Cirrhosis

    • Nephrotic syndrome

    • Protein-losing enteropathy (celiac disease, Whipple disease)

  • increased capillary permeability

    • Angioneurotic edema

    • Gastroenteritis

  • increased hydrostatic pressure

    • Portal venous hypertension

  • Zollinger-Ellison syndrome

• HEMORRHAGE

  • vessel injury

    • Ischemia

    • Infarction

    • Trauma

  • vasculitis

    • Connective tissue disease

    • Henoch-Sch nlein purpura

    • Thrombangitis obliterans, irradiation

  • hypocoagulability

    • Hemophilia

    • Anticoagulant therapy

    • Hypofibrinogemia

    • Circulating anticoagulants

    • Fibrinolytic system activation

    • Idiopathic thrombocytopenic purpura

    • Coagulation defects (leukemia, lymphoma, multiple myeloma, metastatic carcinoma)

    • Hypoprothrombinembinema

• LYMPHATIC BLOCKAGE

  • Tumor infiltration: lymphoma, pseudolymphoma

  • Irradiation

  • Mesenteric fibrosis

  • Intestinal lymphangiectasia

  • Whipple disease

• DEPOSITS

  • Eosinophilic enteritis

  • Pneumatosis intestinalis

  • Amyloidosis

  • Abetalipoproteinemia

  • Crohn disease

  • Graft-versus-host disease

  • Immunologic deficiency: hypo-/dysgammaglobulinemia

Thickened Irregular Folds Dilatation

• INFLAMMATION

  • Crohn disease

• NEOPLASTIC

  • Lymphoma, pseudolymphoma

• INFECTION

  • protozoan

    • giardiasis, strongyloidiasis, hookworm

  • bacterial

    • Yersinia enterocolitica, typhoid fever, tuberculosis

  • fungal: histoplasmosis

  • AIDS-related infection

• IDIOPATHIC

  • lymphatic dilatation

    • Lymphangiectasia

    • Inflammatory process, tumor growth, irradiation fibrosis

    • Whipple disease

  • cellular infiltration

    • Eosinophilic enteritis

    • Mastocytosis

  • deposits

    • Zollinger-Ellison syndrome

    • Amyloidosis

    • Alpha chain disease: defective secretory IgA system

    • A- -lipoproteinemia: recessive, retinitis pigmentosa, neurologic disease

    • A- -lipoproteinemia

    • Fibrocystic disease of the pancreas

    • Polyposis syndrome

mnemonic:

G. WILLIAMS

• Giardiasis

• Whipple disease, Waldenstr m macroglobulinemia

• Ischemia

• Lymphangiectasia

• Lymphoma

• Inflammation

• Amyloidosis, Agammaglobulinemia

• Mastocytosis, Malabsorption

• Soft-tissue neoplasm (carcinoid, lipoma)

Tethered Folds

• = indicative of desmoplastic reaction

• kinking, angulation, tethering, separation of bowel loops

• 1. Carcinoid

• 2. Postoperative in Gardner syndrome

• 3. Retractile mesenteritis

• 4. Hodgkin disease

• 5. Peritoneal implants

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• 6. Endometriosis

• 7. Tuberculous peritonitis

• 8. Mesothelioma

• 9. Postoperative adhesions

Atrophy of Small Bowel Folds

• Chronic malabsorption: celiac disease

• Chronic ischemic changes: radiation injury, amyloidosis

• Crohn disease in burned-out stage

• Parasitic infestation: strongyloidiasis

• Graft-versus-host disease

Ribbonlike Small Bowel

• = featureless/tubular nature of small bowel with effacement of folds

• 1. Graft-versus-host disease

• 2. Celiac disease

• 3. Small bowel infection (eg, viral enteritis)

• 4. Injury from radiation/corrosive medication

• 5. Allergy (eg, soybeans)

• 6. Ischemia

• 7. Amyloid, mastocytosis

• 8. Lymphoma, pseudolymphoma

• 9. Crohn disease

Delayed Small Bowel Transit

• = transit time >6 hours

mnemonic:

SPATS DID

• Scleroderma

• Potassium (hypokalemia)

• Anxiety

• Thyroid (hypothyroidism)

• Sprue

• Diabetes (poorly controlled)

• Idiopathic

• Drugs (opiates, atropine, phenothiazine)

Constricting Lesion of Small Bowel

• Primary adenocarcinoma (proximal jejunum)

• Carcinoid (distal ileum)

• Lymphoma, metastasis

• Endometriosis

• Adhesion, mucosal diaphragm

• Strictures: Crohn disease, radiation enteritis, ischemia, potassium chloride tablets

Multiple Stenotic Lesions of Small Bowel

• Crohn disease

• End-stage radiation enteritis

• Metastatic carcinoma

• Endometriosis

• Eosinophilic gastroenteritis

• Tuberculosis

• Drug-induced (eg, potassium chloride tablets, NSAIDs)

Small Bowel Filling Defects

Solitary Filling Defect of Small Bowel

• INTRINSIC TO BOWEL WALL

  • benign neoplasm: leiomyoma (97%), adenoma, lipoma, hemangioma, neurofibroma

  • malignant primary: adenocarcinoma, lymphoma (desmoplastic response), sarcoma, carcinoid

  • metastases: from melanoma, lung, kidney, breast

  • inflammation: inflammatory pseudotumor

  • infection: parasites

• EXTRINSIC TO BOWEL WALL

  • Duplication cyst

  • Endometrioma

• INTRALUMINAL

  • Gallstone ileus

  • Parasites (ascariasis, strongyloidiasis)

  • Inverted Meckel diverticulum

  • Blood clot

  • Foreign body, bezoar, pills, seeds

Multiple Filling Defects of Small Bowel

• POLYPOSIS SYNDROMES

  • Peutz-Jeghers syndrome

  • Gardner syndrome

  • Disseminated gastrointestinal polyposis

  • Generalized gastrointestinal juvenile polyposis

  • Cronkhite-Canada syndrome

• BENIGN TUMORS

  • Multiple simple adenomatous polyps

  • Hemangioma, blue rubber bleb nevus syndrome

  • Leiomyoma, neurofibroma, lipoma

  • Nodular lymphoid hyperplasia

    • = normal terminal ileum in children + adolescents; may be associated with dysgammaglobulinemia

    • symmetric fairly sharply demarcated filling defects

  • Varices (= multiple phlebectasia in jejunum, oral mucosa, tongue, scrotum)

• MALIGNANT TUMORS

  • Carcinoid tumor

  • Lymphoma

    • primary lymphoma (rarely multiple)

    • secondary lymphoma: gastrointestinal involvement in 63% of disseminated disease; 19% in small intestine

  • Kaposi sarcoma

  • Submucosal metastases: melanoma > lung > breast > choriocarcinoma > kidney > stomach, uterus, ovary, pancreas

• INTRALUMINAL

  • Gallstones

  • Foreign bodies, food particles, seeds, pills

  • Parasites: ascariasis, strongyloidiasis, hookworm, tapeworm

Sandlike Lucencies of Small Bowel

• Waldenstr m macroglobulinemia

• Mastocytosis

• Histoplasmosis

• Nodular lymphoid hyperplasia

• Intestinal lymphangiectasia

• Eosinophilic gastroenteritis

• Lymphoma

• Crohn disease

• Whipple disease

• Yersinia enterocolitis

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P.780




• Cronkhite-Canada syndrome

• Cystic fibrosis

• Food particles/gas bubbles

• Strongyloides stercoralis

ABNORMAL SMALL BOWEL CALIBER & CONTOUR

Small Bowel Tumors

Incidence:

1:100,000; 1.5 6% of all GI neoplasms

• Malignant:benign = 1:1

• Symptomatic malignant:symptomatic benign = 3:1

• Location of small bowel primaries:

  • ileum (41%), jejunum (36%), duodenum (18%)

ROENTGENOGRAPHIC APPEARANCE:

• pedunculated intraluminal tumor, usually originating from mucosa

  • smooth/irregular surface without visible mucosal pattern

  • moves within intestinal lumen twice the length of the stalk

• sessile intraluminal tumor without stalk, usually from tissues outside mucosa

  • smooth/irregular surface without visible mucosal pattern

• intra-/extramural tumor

  • base of tumor greater than any part projecting into the lumen

  • mucosal pattern visible, may be stretched

• serosal tumor

  • displacement of adjacent loops

  • small bowel obstruction (rare)

  • coil-spring pattern of intussusceptum

CT:

• small bowel wall >1.5 cm thick

Cx:

small-bowel obstruction (in up to 10%)

Benign Small Bowel Tumors

• asymptomatic (80%)

• melena, intermittent abdominal pain, weakness

• palpable abdominal mass (20%)

Types:

• Leiomyoma (36 49%)

  Location:

  any segment

• Adenoma (15 20%)

• Lipoma (14 16%)

  Location:

  duodenum (32%), jejunum (17%), ileum (51%)
  fat-density on CT

• Hemangioma (13 16%)

• Lymphangioma (5%)

  Location:

  duodenum > jejunum > ileum

• Neurogenic tumor (1%)

Malignant Small Bowel Tumors

At risk:

Crohn disease, celiac disease, polyposis syndromes, history of small-bowel diverting surgery

• asymptomatic (10 30%)

• pain due to intermittent obstruction (80%)

• weight loss (66%)

• gastrointestinal blood loss (50%)

• palpable abdominal mass (50%)

PRIMARY MALIGNANT SMALL BOWEL TUMOR

• Carcinoid (25 41%)

  • Most common primary small bowel tumor!

    Location:

    predominantly distal ileum

  • calcified mesenteric mass on CT

• Adenocarcinoma (25 26%)

  Location:

  duodenum (48%), jejunum (44%), ileum (8%)

• Non-Hodgkin lymphoma (16 17%)

  • 2nd most common location after stomach

  • aneurysmal dilatation

• Gastrointestinal stromal tumor (GIST)

• = leiomyosarcoma (9 10%)

  Location:

  ileum (50%)

• Vascular malignancy (1%)

• Fibrosarcoma (0.3%)

Secondary Malignant Small Bowel Tumor

• Most common neoplasm of small intestines!

Cecum

Primary Neoplasm of the Appendix

• Mucinous adenoma (44%)/adenocarcinoma (23%)

• Colonic-type adenocarcinoma (13%)

• NHL

• Carcinoid tumor

Incidence:

0.5 1.0% of appendectomy specimens

• appendicitis symptomatology (30 50%)

• appendiceal diameter increased >15 mm (86%)

• cystic dilatation of appendix (mucocele)

• soft-tissue mass

• appendiceal wall thickening

• periappendiceal fat stranding

Ileocecal Valve Abnormalities

• Lipomatosis: >40 years of age, female

  • stellate/rosette pattern

• NEOPLASM

  • Lipoma, adenomatous polyp, villous adenoma

  • Carcinoid tumor

  • Adenocarcinoma: 2% of all colonic cancers

  • Lymphoma: often involving terminal ileum

• INFLAMMATION

  • Crohn disease

  • Ulcerative colitis

    • patulous valve, fixed in open position

  • Tuberculosis

  • Amebiasis

    • terminal ileum not involved (in USA)

  • Typhoid fever, anisakiasis, schistosomiasis, actinomycosis

  • Cathartic abuse

• PROLAPSE

  • antegrade: indistinguishable from lipomatosis/prolapsing mucosa/neoplasm

  • retrograde

• INTUSSUSCEPTION

• LYMPHOID HYPERPLASIA

P.781

Coned Cecum

• INFLAMMATION

  • Crohn disease

    • involvement of ascending colon + terminal ileum

  • Ulcerative colitis

    • backwash ileitis (in 10%)

    • gaping ileocecal valve

  • Appendicitis

  • Typhlitis

  • Perforated cecal diverticulum

• INFECTION

  • Tuberculosis

    • colonic involvement more prominent than that of terminal ileum

  • Amebiasis

    • involvement of cecum in 90% of amebiasis

    • thickened ileocecal valve fixed in open position

    • reflux into normal terminal ileum

    • skip lesions in colon

  • Actinomycosis

    • palpable abdominal mass

    • indolent sinus tracts in abdominal wall

  • Blastomycosis

  • Anisakiasis

  • Typhoid, Yersinia

• TUMOR

  • Carcinoma of the cecum

  • Metastasis to cecum

Cecal Filling Defect

• ABNORMALITIES OF THE APPENDIX

  • Acute appendicitis/appendiceal abscess

  • Crohn disease

  • Inverted appendiceal stump/appendiceal intussusception

  • Mucocele

  • Myxoglobulosis

  • Appendiceal neoplasm: carcinoid tumor (90%), leiomyoma, neuroma, lipoma, adenocarcinoma, metastasis

• COLONIC LESION

  • Ameboma

  • Primary cecal neoplasm

  • Ileocolic intussusception

  • Lipomatosis of ileocecal valve

• UNUSUAL ABNORMALITIES

  • Ileocecal diverticulitis (in 50% < age 30 years)

  • Solitary benign ulcer of the cecum

  • Adherent fecolith (eg, in cystic fibrosis)

  • Endometriosis

  • Burkitt lymphoma

mnemonic:

CECUM TIP SALE

• Carcinoma

• Enteritis

• Carcinoid

• Ulcerative colitis

• Mucocele of appendix

• Tuberculosis

• Intussusception

• Periappendiceal abscess

• Stump of the appendix

• Ameboma

• Lymphoma

• Endometriosis

Appendiceal Intussusception

• Mucocele

• Endometrioma

• Fecolith

• Foreign body

• Polyp (juvenile, inflammatory)

• Papilloma

• Adenoma/adenocarcinoma

• Carcinoid tumor

• Postappendectomy stump

Pericecal Fat-Stranding on CT

• Appendicitis

• Crohn disease

• Tuboovarian abscess

• Cecal diverticulitis

• Perforated cecal carcinoma

Colon

Colon Transit Time

Sitzmarks diagnostic test:

Indication:

adults with severe constipation but otherwise normal GI examination

• 1. Withhold laxatives/enemas/suppositories for 5 days

• 2. Patient takes 1 capsule (contains 24 radiopaque polyvinyl chloride markers of 1 4.5 mm)

• 3. Take KUB on day 3 and 5 to determine location + extent of marker elimination

  • 19 markers (80%) expelled = grossly normal colonic transit time

  • markers scattered about the colon = colonic hypomotility/inertia

  • markers in rectum/rectosigmoid = functional outlet obstruction (eg, internal rectal prolapse/anismus)

  • 5 markers (20%) retained need follow-up KUB on day 7

• All markers are usually in colon by 12 hours

Colon Cutoff Sign

• = abrupt termination of colonic gas column at splenic flexure with decompression of the distal colon due to spasm + obstruction at the splenic flexure impinging on a paralytic transverse colon

• IMPINGEMENT VIA PHRENICOCOLIC LIGAMENT

  • Acute pancreatitis/postpancreatitic stricture

  • Pancreatic/gastric carcinoma

  • Hemorrhage from rupture of splenic artery/abdominal aortic aneurysm

• COLONIC DISEASE

  • Colon cancer

  • Mesenteric thrombosis

  • Ischemic colitis

  P.782

  
  

  • Perforated appendicitis (in 20%)

    N.B.:

    amputation of gas at the hepatic flexure due to spastic ascending colon

Colonic Thumbprinting

• = sharply defined fingerlike marginal indentations at contours of wall

• 1. ISCHEMIA = Ischemic colitis

  • occlusive vascular disease, hypercoagulability state, hemorrhage into bowel wall (bleeding diathesis, anticoagulants), traumatic intramural hematoma

• 2. INFLAMMATION

  • ulcerative colitis, Crohn colitis

• 3. INFECTION

  • acute amebiasis, schistosomiasis, strongyloidiasis, cytomegalovirus (in renal transplant recipients), pseudomembranous colitis

• 4. MALIGNANT LESIONS

  • localized primary lymphoma, hematogenous metastases

• 5. MISCELLANEOUS

  • endometriosis, amyloidosis, pneumatosis intestinalis, diverticulosis, diverticulitis, hereditary angioneurotic edema

mnemonic:

PSALM II

• Pseudomembranous colitis

• Schistosomiasis

• Amebic colitis

• Lymphoma

• Metastases (to colon)

• Ischemic colitis

• Inflammatory bowel disease

Colonic Urticaria Pattern

• OBSTRUCTION

  • Obstructing carcinoma

  • Cecal volvulus

  • Colonic ileus

• ISCHEMIA

• INFECTION/INFLAMMATION

  • Yersinia enterocolitis

  • Herpes

  • Crohn disease

• URTICARIA

Colonic Ulcers

• IDIOPATHIC

  • Ulcerative colitis

  • Crohn colitis

• ISCHEMIC

  • Ischemic colitis

• TRAUMATIC

  • Radiation injury

  • Caustic colitis

• NEOPLASTIC

  • Primary colonic carcinoma

  • Metastases (prostate, stomach, lymphoma, leukemia)

• INFLAMMATORY

  • Pseudomembranous colitis

  • Pancreatitis

  • Diverticulitis

  • Beh et syndrome

  • Solitary rectal ulcer syndrome

  • Nonspecific benign ulceration

• INFECTION

  • protozoan

    • Amebiasis

    • Schistosomiasis

    • Strongyloidiasis

  • bacterial

    • Shigellosis, salmonellosis

    • Staphylococcal colitis

    • Tuberculosis

    • Gonorrheal proctitis

    • Yersinia colitis

    • Campylobacter fetus colitis

  • fungal

    • histoplasmosis, mucormycosis, actinomycosis, candidiasis

  • viral

    • Lymphogranuloma venereum

    • Herpes proctocolitis

    • Cytomegalovirus (transplants)

Aphthous Ulcers of Colon

• Crohn disease

• Amebic colitis

• Yersinia enterocolitis

  Organism:	gram-negative fever, diarrhea, RLQ pain
  Location:	terminal ileum thickened folds + ulceration lymphoid nodular hyperplasia

• Salmonella, shigella infection

• Herpes virus infection

• Beh et syndrome

• Lymphoma

• Ischemia

Multiple Bull's-eye Lesions of Colonic Wall

mnemonic:

MaCK CLaN

• Melanoma and

• Carcinoma

• Kaposi sarcoma

• Carcinoid

• Lymphoma and

• Neurofibromatosis

Double-Tracking of Colon

• = longitudinal extraluminal tracks paralleling the colon

• 1. Diverticulitis: generally 3 6 cm in length

• 2. Crohn disease: generally >10 cm

• 3. Ulcerative colitis

• 4. Primary carcinoma: wider + more irregular

Colonic Narrowing

• CHRONIC STAGE OF ANY ULCERATING COLITIS

  • inflammatory:

    • Ulcerative colitis

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    • Crohn colitis

    • Solitary rectal ulcer syndrome

    • Nonspecific benign ulcer

  • infectious:

    • Amebiasis

    • Schistosomiasis

    • Bacillary dysentery

    • Tuberculosis

    • Fungal disease

    • Lymphogranuloma venereum

    • Herpes zoster

    • Cytomegalovirus

    • Strongyloides

  • ischemic

    • Ischemic colitis

  • traumatic

    • Radiation injury

    • Cathartic colon

    • Caustic colitis

• MALIGNANT LESION

  • primary

    • Colonic carcinoma (annular/scirrhous)

    • Complication of ulcerative colitis + Crohn colitis

  • metastatic:

    • from prostate, cervix, uterus, kidney, stomach, pancreas, primary intraperitoneal sarcoma

    • hematogenous (eg, breast)

    • lymphangitic spread

    • peritoneal seeding

• EXTRINSIC PROCESS

  • inflammation

    • Retractile mesenteritis

    • Diverticulitis

    • Pancreatitis

  • deposits

    • Amyloidosis

    • Endometriosis

    • Pelvic lipomatosis

• POSTSURGICAL

  • Adhesive bands

  • Surgical anastomosis

• NORMAL

  • Cannon point

Localized Colonic Narrowing

mnemonic:

SCARED CELL-MATE

• Schistosomiasis

• Carcinoid

• Actinomycosis

• Radiation

• Endometriosis

• Diverticulitis

• Colitis

• Extrinsic lesion

• Lymphoma

• Lymphogranuloma venereum

• Metastasis

• Adenocarcinoma

• Tuberculosis

• Entamoeba histolytica

Microcolon

mnemonic:

MI MCA

• Meconium ileus, Meconium peritonitis (cystic fibrosis)

• Ileal/jejunal atresia

• Megacystis-microcolon-hypoperistalsis syndrome

• Colonic atresia (distal to atretic segment)

• Aganglionosis (Hirschsprung disease)

Colonic Filling defects

Submucosal Tumor of Colon

• Lipoma

• Carcinoid

• Leiomyoma

• Lymphangioma, hemangioma

Single Colonic Filling Defect

• BENIGN TUMOR

  • Polyp

    • (hyperplastic, adenomatous, villous adenoma, villoglandular); most common benign tumor

  • Lipoma

    • Most common intramural tumor; 2nd most common benign tumor; M < F

    Location:

    ascending colon + cecum > left side of colon

  • Carcinoid: 10% metastasize

  • Spindle cell tumor

    • (leiomyoma, fibroma, neurofibroma); 4th most common benign tumor; rectum > cecum

  • Lymphangioma, hemangioma

• MALIGNANT TUMOR

  • primary tumor:

    • carcinoma, sarcoma

  • secondary tumor:

    • metastases (breast, stomach, lung, pancreas, kidney, female genital tract), lymphoma, invasion by adjacent tumors

• INFECTION

  • Ameboma

  • Polypoid granuloma: schistosomiasis, TB

• INFLAMMATION

  • Inflammatory pseudopolyp: ulcerative colitis, Crohn disease

  • Periappendiceal abscess

  • Diverticulitis

  • Foreign-body perforation

• NONSESSILE INTRALUMINAL BODY

  • Fecal impaction

  • Foreign body

  • Gallstone

  • Bolus of Ascaris worms

• MISCELLANEOUS

  • Endometriosis

    • 3rd most common benign tumor

    Location:

    sigmoid colon, rectosigmoid junction (at level of cul-de-sac)
    may cause bleeding (after invasion of mucosa)

  • Localized amyloid deposition

  • Suture granuloma

  P.784

  
  

  • Intussusception

  • Pseudotumor (adhesions, fibrous bands)

  • Colitis cystica profunda

Multiple Colonic Filling Defects

• NEOPLASMS

  • polyposis syndrome:

    • familial polyposis, Gardner syndrome, Peutz-Jeghers syndrome, Turcot syndrome, juvenile polyposis syndrome, disseminated gastrointestinal polyps, multiple adenomatous polyps

  • hematogenous metastases:

    • from breast, lung, stomach, ovary, pancreas, uterus

  • multiple tumors

    • benign:

      • neurofibromatosis, colonic lipomatosis, multiple hamartoma syndrome (Cowden disease)

    • malignant:

      • lymphoma, leukemia, adenocarcinoma

• INFLAMMATORY PSEUDOPOLYPS

  • ulcerative colitis, Crohn colitis, ischemic colitis, amebiasis, schistosomiasis, strongyloidiasis, trichuriasis

• ARTIFACTS

  • feces, air bubbles, oil bubbles, mucous strands, ingested foreign body (eg, corn kernels)

• MISCELLANEOUS

  • nodular lymphoid hyperplasia, lymphoid follicular pattern, hemorrhoids, diverticula, pneumatosis intestinalis, colitis cystica profunda, colonic urticaria, submucosal colonic edema secondary to obstruction, cystic fibrosis, amyloidosis, ulcerative pseudopolyps, proximal to obstruction

mnemonic:

MILL P3

• Metastases (to colon)

• Ischemia (thumbprinting)

• Lymphoma

• Lymphoid hyperplasia

• Polyposis

• Pseudopolyposis (with inflammatory bowel disease)

• Pneumatosis cystoides

Carpet Lesions of Colon

• = flat lobulated lesions with alteration of surface texture + little/no protrusion into lumen

Location:

rectum > cecum > ascending colon

Cause:

• NEOPLASM

  • Tubular/tubulovillous/villous adenoma

  • Familial polyposis

  • Adenocarcinoma

  • Submucosal tumor spread (from adjacent carcinoma)

• MISCELLANEOUS

  • Nonspecific follicular proctitis

  • Biopsy site

  • Endometriosis

  • Rectal varices

  • Colonic urticaria

Colonic Polyp

Terminology:

• Polyp

  • = mass projecting into the lumen of a hollow viscus above the level of the mucosa; usually arises from mucosa, may derive from submucosa/muscularis propria

  • (a) neoplastic: adenoma/carcinoma

  • (b) nonneoplastic: hamartoma/inflammatory polyp

• Pseudopolyp

  • = scattered island of inflamed edematous mucosa on a background of denuded mucosa

  • (a) pseudopolyposis of ulcerative colitis

  • (b) cobblestoning of Crohn disease

• Postinflammatory (filiform) polyp

  • = fingerlike projection of submucosa covered by mucosa on all sides following healing + regeneration of inflammatory (most common in ulcerative colitis)/ischemic/infectious bowel disease

Histologic classification:

• ADENOMATOUS POLYPS

  • = Familial adenomatous polyposis syndrome

    Cause:	abnormality on chromosome 5
    Cx:	adenomatous polyps are premalignant eventually leading to colorectal carcinoma

  • 1. Familial (multiple) polyposis

  • 2. Gardner syndrome

  • 3. Turcot syndrome

• HAMARTOMATOUS POLYPS

  • = Hamartomatous polyposis syndromes

  • 1. Peutz-Jeghers syndrome (most in small bowel)*

  • 2. Cowden disease*

  • 3. Juvenile polyposis*

  • 4. Cronkhite-Canada syndrome

  • 5. Bannayan-Riley-Ruvalcaba syndrome

• POLYPOSIS LOOK-ALIKES

  • Inflammatory polyposis

  • Lymphoid hyperplasia

  • Lymphoma

  • Metastases

  • Pneumatosis coli

Polyposis Syndromes

• = more than 100 polyps in number

Mode of transmission:

• HEREDITARY

  • autosomal dominant

    • Familial (multiple) polyposis

    • Gardner syndrome

    • Peutz-Jeghers syndrome

    • Juvenile polyposis coli

  • autosomal recessive

    • Turcot syndrome

• NONHEREDITARY

  • Cronkhite-Canada syndrome

  • Juvenile polyposis

P.785

Differential Diagnosis of Colonic polyps
Single Polyp		Multiple Polyps
Neoplastic (10%)
epithelial (adenomatous)	Tubular adenoma Tubulovillous adenoma Villous adenoma	Familial multiple polyposis Adenomatosis of GI tract Gardner syndrome Turcot syndrome
nonepithelial	Carcinoid Leiomyoma Lipoma Hemangioma, lymphangioma Fibroma, neurofibroma
Nonneoplastic (90%)
unclassified	Hyperplastic polyp	Hyperplastic polyposis
hamartomatous	Juvenile polyps	Juvenile polyposis Peutz-Jeghers syndrome Cronkhite-Canada syndrome
inflammatory	Benign lymphoid polyp Fibroid granulation polyp	Ulcerative colitis

Mural Stratification of Intestinal Tract

• = bowel wall thickening with abnormal separation of bowel layers on cross-sectional imaging

• CECT:

  • double halo/target sign during arterial phase:

    • contrast enhancement of inner layer:

      • (1) mucosa + (2) muscularis propria

    • interposed edema (water)/hemorrhage (blood)/inflammatory cell infiltrate (pus, cells)/fatty proliferation:

      • (3) submucosa

    • contrast enhancement of outer layer:

      • (4) muscularis propria + (5) serosa

• Cause:

  • Tumor has not been reported to cause stratification!

  • EDEMA

    • low-density/water-density separation

    • 1. Ulcerative colitis (50%): rectum

    • 2. Proximal to obstructing tumor/intussusception

  • INFLAMMATORY CELL INFILTRATE

    • Crohn disease (in up to 50%)

    • Mycobacterium tuberculosis

    • Eosinophilic enteritis

    • Cytomegalovirus

    • Clostridium difficile

    • Entamoeba histolytica

    • Vibrio cholerae

    • Shigella

    • Escherichia coli

  • ISCHEMIA/INFARCTION

    • Arterial obstruction: thromboembolism, plaque thrombus

    • Peripheral vasculopathy

    • Venous obstruction: thrombosis, bowel torsion, closed-loop obstruction

    • Hypoperfusion: proximal arterial stenosis potentiated by myocardial infarction, bradycardia, dehydration

      N.B.:

      closed-loop obstruction with signs of bowel infarction is a surgical condition!

      • signs of bowel infarction:

        • free peritoneal fluid

        • asymmetric bowel wall enhancement

        • persistent enhancement of bowel wall/segmental arteries

        • arterial/venous filling defects

        • increased density of mesentery

        • bowel obstruction

  • INTESTINAL WALL HEMORRHAGE

    • Anticoagulation

    • Blood dyscrasia: thrombocytopenic purpura

    • Blunt trauma

      • snow-cone appearance of duodenum

Pseudomembranous Colitis

• Clostridium difficile

• Ischemic colitis: acute/subacute

• Staphylococcus

• Shigella

• Pseudomonas aeruginosa

6. Drugs:

chlorpropamide, mercuric compounds, gold, NSAIDs

Accordion Sign

• = gross irregular polypoid thickening of colonic wall with wide separation of inner + outer walls

• Radiation-induced colitis

• Ischemic colitis

• Infectious colitis: Clostridium difficile, tuberculosis

• Typhlitis, neutropenic colitis

• Inflammation: Crohn disease, ulcerative colitis

  • The only 2 conditions with wall thickening >10 mm

P.786




• Lymphangiectasia

• Intramural hemorrhage

Rectum & Anus

Rectal Narrowing

• Pelvic lipomatosis + fibrolipomatosis

• Lymphogranuloma venereum

• Radiation injury of rectum

• Chronic ulcerative colitis

Enlarged Presacral Space

• Normal width <5 mm in 95%; abnormal width >10 mm

• RECTAL INFLAMMATION/INFECTION

  • ulcerative colitis, Crohn colitis, idiopathic proctosigmoiditis, radiation therapy

• RECTAL INFECTION

  • Proctitis (TB, amebiasis, lymphogranuloma venereum, radiation, ischemia)

  • Diverticulitis

• BENIGN RECTAL TUMOR

  • Developmental cyst (dermoid, enteric cyst, tailgut cyst)

  • Lipoma, neurofibroma, hemangioendothelioma

  • Epidermal cyst

  • Rectal duplication

• MALIGNANT RECTAL TUMOR

  • Adenocarcinoma, cloacogenic carcinoma

  • Lymphoma, sarcoma, lymph node metastases

  • Prostatic carcinoma, bladder tumors, cervical cancer, ovarian cancer

• BODY FLUIDS/DEPOSITS

  • Hematoma: surgery, sacral fracture

  • Pus: perforated appendix, presacral abscess

  • Serum: edema, venous thrombosis

  • Deposit of fat: pelvic lipomatosis, Cushing disease

  • Deposit of amyloid: amyloidosis

• SACRAL TUMOR

  • Sacrococcygeal teratoma, anterior sacral meningocele

  • Chordoma, metastasis to sacrum

• MISCELLANEOUS

  • Inguinal hernia containing segment of colon

  • Colitis cystica profunda

  • Pelvic lipomatosis

Lesions of Ischiorectal Fossa

• Congenital and developmental anomalies

  • Gartner duct cyst

  • Klippel-Trenaunay syndrome

  • Tailgut cyst

• Inflammatory and hemorrhagic lesions

  • Fistula in ano

  • Ischiorectal/perirectal abscess

  • Extraperitoneal pelvic hematoma

  • Rectal perforation

• Secondary neoplasm

  • per direct extension/hematogenous spread:

    • anorectal/prostatic/pelvic/sacral tumor; lung cancer; melanoma; lymphoma

• Primary neoplasm

  • Aggressive angiomyxoma

  • Lipoma

  • Plexiform neurofibroma

  • Anal adenocarcinoma

  • Squamous cell carcinoma

Peritoneum

Peritoneal Mass

• SOLID MASS

  • Peritoneal mesothelioma

  • Peritoneal carcinomatosis

• INFILTRATIVE PATTERN

  • Peritoneal mesothelioma

• CYSTIC MASS

  • Cystic mesothelioma

  • Pseudomyxoma peritonei

  • Bacterial/mycobacterial infection

Multiple Peritoneal Masses

• Metastases: RCC

• Endometriosis

• Abdominal lymphoma

Mesentery & Omentum

Short Mesentery

• = shortened line of fixation

• 1. Malrotation + midgut volvulus

• 2. Omphalocele

• 3. Gastroschisis

• 4. Congenital diaphragmatic hernia

• 5. Asplenia + polysplenia

Apple peel Small Bowel

• = distal small intestines spirals around its vascular supply resembling an apple peel resulting in a very short intestine

• 1. Proximal jejunal atresia

• 2. Absence of distal superior mesenteric artery

• 3. Shortening of small bowel distal to atresia

• 4. Absence of dorsal mesentery

Cx:	propensity toward necrotizing enterocolitis
Prognosis:	high mortality

Omental Mass

• 33% of primary omental tumors are malignant!

• Secondary neoplasms are more frequent than primary!

• SOLID MASS

  • benign

    • Leiomyoma

    • Lipoma

    • Neurofibroma

  • malignant

    • Leiomyosarcoma

    • Liposarcoma

    • Fibrosarcoma

    • Lymphoma

    • Peritoneal mesothelioma

    • Hemangiopericytoma

    • Metastases

  • Infection: tuberculosis

P.787




• CYSTIC MASS

  • Hematoma

  • Cystic mesothelioma

Omental Cake

• = replacement of normal fat of the greater omentum by a soft-tissue density

• Peritoneal metastases

  mnemonic:

  COPS

  • Colon

  • Ovary

  • Pancreas

  • Stomach

• Lymphoma

• Mesothelioma

• Tuberculosis

Mesenteric Mass

• ROUND SOLID MASSES

  • Benign primary tumors are more common than malignant primary tumors!

  • Secondary neoplasms more frequent than primary

  • Cystic tumors more common than solid tumors!

  • Malignant solid tumors have a tendency to be located near root of mesentery, benign solid tumors in periphery near bowel!

  • 1. Metastases especially from colon, ovary (most frequent neoplasm of mesentery)

  • 2. Lymphoma

  • 3. Leiomyosarcoma (more frequent than leiomyoma)

  • 4. Neural tumor (neurofibroma, ganglioneuroma)

  • 5. Lipoma (uncommon), lipomatosis, liposarcoma

  • 6. Fibrous histiocytoma

  • 7. Hemangioma

  • 8. Desmoid tumor (most common primary)

  • 9. Desmoplastic small round cell tumor of peritoneum

• ILL-DEFINED MASSES

  • Metastases (ovary)

  • Lymphoma

  • Fibromatosis, fibrosing mesenteritis (associated with Gardner syndrome)

  • Lipodystrophy

  • Mesenteric panniculitis

• STELLATE MASSES

  • 1. Peritoneal mesothelioma

  • 2. Retractile mesenteritis

  • 3. Fibrotic reaction of carcinoid

  • 4. Radiation therapy

  • 5. Desmoid tumor

  • 6. Hodgkin disease

  • 7. Tuberculous peritonitis

  • 8. Ovarian metastases

  • 9. Diverticulitis

  • 10. Pancreatitis

  • A calcified mesenteric mass suggests carcinoid tumor!

• LOCULATED CYSTIC MASSES (2/3)

  • Cystic lymphangioma (most common)

  • Pseudomyxoma peritonei

  • Cystic mesothelioma

  • Mesenteric cyst

  • Mesenteric hematoma

  • Benign cystic teratoma

  • Cystic spindle cell tumor (= centrally necrotic leiomyoma/leiomyosarcoma)

Mesenteric/Omental Cysts

• = BUBBLES OF THE BELLY

• The first step is to determine the organ of origin!

• 1. Lymphangioma

• 2. Nonpancreatic pseudocyst

  • = sequelae of mesenteric/omental hematoma/abscess

  Path:

  thick-walled, usually septated cystic mass with hemorrhagic/purulent contents

• 3. Duplication cyst

• 4. Mesothelial cyst

• 5. Enteric cyst

• 6. Cystic metastasis

• 7. Cystic mesothelioma

Mesenteric Edema/Congestion

• increase of mesenteric fat attenuation to 40 to 60 HU

• loss of sharp interfaces between mesenteric vessels + fat

• SYSTEMIC FLUID OVERLOAD

  • Hypoalbuminemia

  • Liver cirrhosis

  • Nephrosis

  • Heart failure

• LOCAL VESSEL DISEASE

  • Portal vein thrombosis

  • Mesenteric vein/artery thrombosis

  • Vasculitis

  • SMA dissection

• CELL INFILTRATE

  • Malignant neoplasm

  • Inflammation

  • Trauma (small hemorrhage)

Comb Sign

• = vascular dilatation of vasa recta + interconnected arterial arcades aligned as the teeth of a comb

• multiple tubular tortuous opacities on mesenteric side of ileum

• 1. Crohn disease

• 2. Ulcerative colitis

• 3. Vasculitis: Lupus, polyarteritis nodosa, Henoch-Sch nlein syndrome, microscopic polyangiitis, Beh et syndrome

• 4. Mesenteric thromboembolism

• 5. Strangulated bowel obstruction

Fat Ring Sign

• = fat-stranding of the fat plane surrounding the root of mesenteric vessels

• benign

  • Mesenteric panniculitis

  • Mesenteric lipodystrophy

  • Retractile mesenteritis

• malignant

  • Carcinoid

  • Desmoid tumor

  • Lymphoma

P.788

Umbilical Tumor

• PRIMARY (38%)

  • benign/malignant neoplasm, skin tumor

• METASTASES (30%)

  • = Sister Joseph nodule

  • firm painful nodule

  • ulceration with serosanguinous/purulent discharge

  Cause:

  gastrointestinal cancer (50%), undetermined (25%), ovarian cancer, pancreatic cancer, small cell carcinoma of lung (very rare)

  • Spread:

    • direct extension from anterior peritoneal surface

    • extension along embryonic remnants: falciform, median umbilical, omphalomesenteric ligaments

    • hematogenous

    • retrograde lymphatic flow from inguinal, axillary, paraaortic nodes

    • iatrogenic: laparoscopic tract, tract of percutaneous needle biopsy

• NONNEOPLASTIC

  • Endometriosis (32%)

  • Granuloma

  • Incarcerated hernia

Abdominal Lymphadenopathy

Regional Patterns of Lymphadenopathy

• @ Retrocrural nodes

  Abnormal size:	>6 mm
  Common cause:	lung carcinoma, mesothelioma, lymphoma

• @ Gastrohepatic ligament nodes

  • = superior portion of lesser omentum suspending stomach from liver

  Abnormal size:	>8 mm
  Common cause:	carcinoma of lesser curvature of stomach, distal esophagus, lymphoma, pancreatic cancer, melanoma, colon + breast cancer
  DDx:	coronary varices

• @ Porta hepatis nodes

  • = in porta hepatis extending down hepatoduodenal ligament, anterior + posterior to portal vein

  Abnormal size:	>6 mm
  Common cause:	carcinoma of gallbladder + biliary tree, liver, stomach, pancreas, colon, lung, breast
  Cx:	high extrahepatic biliary obstruction

• @ Pancreaticoduodenal nodes

  • = between duodenal sweep + pancreatic head anterior to IVC

  Abnormal size:	>10 mm
  Common cause:	lymphoma, pancreatic head, colon, stomach, lung, breast cancer

• @ Perisplenic nodes

  • = in splenic hilum

  Abnormal size:	>10 mm
  Common cause:	NHL, leukemia, small bowel neoplasm, ovarian cancer, carcinoma of right/transverse colon

• @ Retroperitoneal nodes

  • = periaortic, pericaval, interaortocaval

  Abnormal size:	>10 mm
  Common cause:	lymphoma, renal cell, testicular, cervical, prostatic carcinomas

• @ Celiac and superior mesenteric artery nodes

  • = preaortic nodes

  Abnormal size:	>10 mm
  Common cause:	any intraabdominal neoplasm

• @ Pelvic nodes

  • = along common, external + internal iliac vessels

  Abnormal size:	>15 mm
  Common cause:	carcinoma of bladder, prostate, cervix, uterus, rectum

Low-Attenuation Abdominal Adenopathy

• = ENLARGED LYMPH NODE WITH LOW-DENSITY CENTER

• 1. Mycobacterial infection (TB, M. avium-intracellulare)

• 2. Pyogenic infection

• 3. Whipple disease

• 4. Lymphoma

• 5. Metastatic disease after radiation + chemotherapy

• 6. Lymphangioleiomyomatosis

• 7. Neurofibromatosis type I

• 8. Cavitating mesenteric lymph node syndrome

P.789

Anatomy and Function of Gastrointestinal Tract

Gastrointestinal hormones

Cholecystokinin

• = CCK = 33 amino acid residues (former name: Pancreozymin); the 5 C-terminal amino acids are identical to those of gastrin, causing similar effects as gastrin; 2.5-minute serum half-life

Produced in:	duodenal + upper intestinal mucosa
Released by:	fatty acids, some amino acids (phenylalanine, methionine), hydrogen ions

• Effects:

  • @ Stomach

    • weakly stimulates HCl secretion

    • given alone: inhibits gastrin, which leads to decrease in HCl production

    • stimulates pepsin secretion

    • stimulates gastric motility

  • @ Pancreas

    • stimulates secretion of pancreatic enzymes (= Pancreozymin)

    • stimulates bicarbonate secretion (weakly by direct effect; strongly through potentiating effect on secretin)

    • stimulates insulin release

  • @ Liver

    • stimulates water + bicarbonate secretion

  • @ Intestine

    • stimulates secretion of Brunner glands

    • increases motility

  • @ Biliary tract

    • strong stimulator of gallbladder contraction with maximum effect within 5 15 minutes + return to basal size in 1 hour

    • relaxation of sphincter of Oddi

• Medication:

  • sincalide (Kinevac ) = synthetic C-terminal octapeptide of the hormone cholecystokinin

  Use:

  may be used to empty gallbladder about 30 minutes (to 4 hours) before tracer injection in patients on prolonged fasting (gallbladder atony + retained bile and sludge secondary to absence of endogenously produced CCK)

  • Dose for hepatobiliary scintigraphy:

    • preferred: IV infusion of 0.01 g/kg Kinevac over 30 60 minutes;

    • package insert: with slow IV injection of 0.01 g/kg Kinevac over 3 minutes (concentration of 1 g/mL) the response is too variable

  Useful in:	(a) patient fasting >24 hours/on total parenteral nutrition (b) acalculous cholecystitis (c) chronic GB dysfunction (d) GB ejection fraction
  Side effect:	increase in biliary-to-bowel transit time, dizziness, flushing, nausea, abdominal cramps, urge to defecate

  • Contraindications:

    • acute pancreatitis, acute cholecystitis, obstruction of cystic duct/CBD, appendicitis, peritonitis, pyloric stenosis, peptic ulcer

Gastrin

• = 17 amino acid peptide amide;

• PENTAGASTRIN

  • = acyl derivative of the biologic active C-terminal tetrapeptide amide

Produced in:	antral cells + G cells of pancreas
Released by:	vagal stimulation, gastric distension short-chain alcohol (ethanol, propanol) amino acids (glycine, -alanine) caffeine hypercalcemia mediated by neuroendocrine cholinergic reflexes
Inhibited by:	drop in pH of antral mucosa to <3.5

• Effects:

  • @ Stomach:

    • stimulation of gastric HCl secretion from parietal cells, which in turn:

    • increases pepsinogen production by chief cells through local reflex

    • increase in antral motility

    • trophic effect on gastric mucosa (parietal cell hyperplasia)

  • @ Pancreas

    • strong increase in enzyme output

    • weakly stimulates fluid + bicarbonate output

    • stimulates insulin release

  • @ Liver

    • water + bicarbonate secretion

  • @ Intestine

    • stimulates secretion of Brunner glands

    • increases motility

  • @ Gallbladder

    • stimulates contraction

  • @ Esophagus

    • increases resting pressure of LES

Glucagon

Produced in:	cells (and cells) of pancreas
Released by:	low blood glucose levels

• Effects:

  • @ Intestines

    • lowers pressure of GE sphincter

    • hypotonic effect on duodenum > jejunum > stomach > colon

  • @ Hormones

    • releases catecholamines from the adrenal gland that paralyze intestinal smooth muscle

    • increases serum insulin + glucose levels (mobilization of hepatic glycogen)

  • @ Biliary tract

    • increases bile flow

    P.790

    
    

    • relaxes gallbladder + sphincter of Oddi

Dose for radiologic imaging:

1 mg maximum

• IV administration causes a quick response + rapid dissipation of action!

• IM administration prolongs onset + increases length of action!

Half-life:	3 6 minutes
Side effects:	nausea + vomiting, weakness, dizziness (delayed onset of 1.5 4 hours after IM administration)

• Contraindication:

  • hypersensitivity/allergy to glucagon: urticaria, periorbital edema, respiratory distress, hypotension, coronary artery spasm (?), circulatory arrest

  • known hypertensive response to glucagon

  • pheochromocytoma: glucagon stimulates release of catecholamines

  • insulinoma: insulin-releasing effect may result in hypoglycemia

  • glucagonoma

  • poorly controlled diabetes mellitus

Secretin

Produced in:	duodenal mucosa
Released by:	hydrogen ions providing a pH <4.5

• Effects:

  • @ Stomach

    • inhibits gastrin activity, which leads to decrease in HCl secretion

    • stimulates pepsinogen secretion by chief cells (potent pepsigogue)

    • decreases gastric and duodenal motility + contraction of pyloric sphincter

  • @ Pancreas

    • increases alkaline pancreatic secretions (NaHCO₃)

    • weakly stimulates enzyme secretion

    • stimulates insulin release

  • @ Liver

    • stimulates water + bicarbonate secretion (most potent choleretic)

  • @ Intestine

    • stimulates secretion of Brunner glands

    • inhibits motility

  • @ Esophagus

    • opens LES

Embryology of alimentary tract

Origin:

as a pouchlike extension of the yolk sac

Development of GI tube:

• continuous tubular structure by 6 weeks GA; divided into:

  • foregut (supplied by celiac artery)

  • midgut (supplied by superior mesenteric artery)

  • hindgut (supplied by inferior mesenteric artery)

Rotation about omphalomesenteric vessels by 270 :

• <6 weeks GA

  • 90 counterclockwise rotation of duodenojejunal segment toward the right of SMA

  • 90 counterclockwise rotation of ileocolic segment toward the left of SMA

• during 6th week GA

  • additional 90 counterclockwise rotation of duodenum posterior to SMA

  • remainder of midgut within umbilical cord

• 10 12 weeks GA

  • intestines slides back into peritoneal cavity

  • final 90 counterclockwise rotation of duodenum

  • final 180 counterclockwise rotation of cecum

Peritoneal fixation of small bowel:

• broad-based mesentery extending from ligament of Treitz to ileocecal valve

Stages of Intestinal Rotation

P.791

Blood Supply of Stomach, Duodenum, and Pancreas

Blood Supply of Large Intestine

P.792

Vascular Supply of Bowel

• bowel receives 20% of resting cardiac output (2/3 for intestinal mucosa) which increases up to 35% in postprandial phase

  • earliest + fast rise after intake of carbohydrates

  • slower + large rise after intake of fat + proteins

Celiac Trunk

Supply for:	from distal esophagus to descending duodenum
Anastomosis:	to SMA via gastroduodenal artery as the 1st branch off the celiac trunk

Superior Mesenteric Artery (SMA)

Supply for:	transverse + descending duodenum, jejunum, ileum, large bowel to splenic flexure
Anastomosis:	to IMA via marginal artery of Drummond, arcade of Riolan

Inferior Mesenteric Artery (IMA)

Supply for:	colon from splenic flexure to rectum
Anastomoses:	to lumbar branches of abdominal aorta, sacral artery, internal iliac aa.

Arcades

• up to four arcades are formed by these arteries which continue toward the periphery as

  • Primary parallel circuits for

    • muscularis propria

    • submucosa

    • mucosa

  • Serial circuits of

    • resistance arterioles

    • precapillary sphincters

    • capillaries

    • postcapillary sphincters

    • venous capacitance vessels

Esophagus

Lower Esophageal Anatomy

• Esophageal Vestibule

  • = saccular termination of lower esophagus with upper boundary at tubulovestibular junction + lower boundary at esophagogastric junction

  • collapsed during resting state

  • assumes bulbous configuration with swallowing

  • (a) tubulovestibular junction = A level = junction between tubular and saccular esophagus

  • (b) phrenic ampulla = bell-shaped part above diaphragm (term should be discarded because of dynamic changes of configuration)

  • (c) submerged segment = infrahiatal part of esophagus

    • widening/disappearance is indicative of gastroesophageal reflux disease (GERD)

• Gastroesophageal Junction

  Site:

  at upper level of gastric sling fibers, straddles cardiac incisura demarcating the left lateral margin of GE junction

• Z-line = B level = zigzag-shaped squamocolumnar junction line

  • Not acceptable criterion for locating GE junction

  Site:

  1 2 cm above gastric sling fibers

• Lower Esophageal Sphincter

  • = physiologic 2 4-cm high pressure zone corresponding to esophageal vestibule

  • tightly closed during resting state

  • assumes bulbous configuration with swallowing

Muscular Rings of Esophagus

A Ring

• = contracted/hypertrophied muscles in response to incompetent GE sphincter

• rarely symptomatic/dysphagia

Location:

at tubulovestibular junction = superior aspect of vestibule

• usually 2 cm proximal to GE junction at upper end of vestibule

• varies in caliber during the same examination, may disappear on maximum distension

• broad smooth narrowing with thick rounded margins

• visible only if tubular esophagus above + vestibule below are distended

B Ring

• = sling fibers representing a U-shaped thickening of inner muscle layers with open arm of U toward lesser curvature = inferior aspect of vestibule

Location:

< 2 cm from hiatal margins

• only visible when esophagogastric junction is above hiatus

• thin ledge-like ring just below the mucosal junction (Z-line)

Swallowing function

Technique:	videofluoroscopy of a modified barium swallow study to assess handling of bolus (with consistency of nectar liquid, honey liquid, pureed food, soft solid food, hard solid food); preferably together with speech pathologist
Document patient behavior + reaction:	episode of refusal, cough, silent aspiration, apnea, bradycardia
CNS involved:	cranial nerves V, VII, IX, X, XII; 5 cervical nerves; cortical + subcortical pathways; midbrain; brainstem
Muscles involved:	32 groups of muscles
Developmental:	swallowing as early as 11 weeks GA; suckling at 18 24 weeks GA; nonnutritive sucking at 27 28 weeks GA; single breath sucking at 35 36 weeks GA

Phases:

• Oral preparatory phase

  • food chewed + mixed with saliva

• Oral phase

  • bolus propelled posteriorly to tongue

  • Path:

    • spillage from mouth

    • small bolus formation

    • tongue tremor

    • incomplete tongue elevation

    • early spillage into valleculae prior to initiation of swallow

P.793




• Pharyngeal phase

  • elevation of soft palate + valleculae (to seal nasopharynx)

  • elevation of larynx (to close vestibule)

  • relaxation of cricopharyngeal muscle

  • contraction of lateral pharyngeal wall

  • Path:

    • nasopharyngeal reflux

    • laryngeal penetration (= contrast material enters laryngeal vestibule

      Cause:

      delayed elevation of larynx

    • tracheal aspiration (= contrast material enters airway below vocal cord level)

      Cause:

      delayed elevation of larynx, delayed pharyngeal transit time, decreased clearance of bolus with residual in vallecula + pyriform sinus spilling into larynx + trachea

• Esophageal phase

  • contraction of cricopharyngeal muscle

  • bolus transfer into esophagus

  Path:

  cricopharyngeal achalasia (with reflux of bolus into oropharynx/pooling in pyriform sinus)

Stomach

Gastric cells

• Chief cells

  • = peptic/zymogenic cells

  Location:	body + fundus
  produce:	pepsinogen

• Parietal cells

  • = oxyntic cells

  Location:	body + fundus
  produce:	H+, Cl-, intrinsic factor, prostaglandins

• Mucous neck cells

  produce:

  mucoprotein, mucopolysaccharide, aminopolysaccharide sulfate

• Argentaffine cells

  • = enteroendocrine cells

  Location:	body + fundus
  produce:	glucagon-like substance (A-cells), somatostatin (D-cells), vasoactive intestinal polypeptide (D1-cells), 5-hydroxytryptamine (EC-cells)

• G-cells

  Location:	pylorus
  produce:	gastrin

Effect of Bilateral Vagotomy

• = cholinergic denervation

• (1) decreased MOTILITY of stomach + intestines

• (2) decreased GASTRIC SECRETION

• (3) decreased TONE OF GALLBLADDER + bile ducts

• (4) increased TONE OF SPHINCTERS (Oddi + lower esophageal sphincter)

Pylorus

• = fan-shaped specialized circular muscle fibers with:

  • distal sphincteric loop = right canalis loop

    • corresponds to radiologic pyloric sphincter

  • proximal sphincteric loop = left canalis loop

    • 2 cm proximal to distal sphincteric loop on greater curvature (seen during complete relaxation)

  • torus

    • = fibers of both sphincters converge on the lesser curvature side to form a muscular prominence; prolapse of mucosa between sphincteric loops produces a niche simulating ulcer

• pyloric channel 5 10 mm long, wall thickness of 4 8 mm

• concentric indentation of the base of the duodenal bulb

Pyloric Muscular Anatomy

Small Bowel

• Longest tubular organ in body measuring 550 600 cm (18 22 feet) in length

Segments:	duodenum of 25 30 cm in length jejunum of 10 12 feet in length (= proximal 60%) ileum of 6 8 feet in length (= distal 40%)
Mesentery:	15 cm long between ligament of Treitz + ileocecal junction

Duodenal Segments

• duodenal bulb + short postbulbar segment:

  • intraperitoneal + freely movable

• descending duodenum:

  • retroperitoneal attached to head of pancreas

• horizontal = transverse segment:

  • retroperitoneal crossing the spine

• ascending portion

  • retroperitoneal ascending to level of duodenojejunal junction

• VARIATIONS:

  • mobile duodenum / water-trap duodenum

    • = long postbulbar segment with undulation/redundancy

  • duodenum inversum/duodenum reflexum

    • = distal duodenum ascends to the right of spine to the level of duodenal bulb + then crosses spine horizontally + fixated in normal location

Small Bowel Folds

• Circular small bowel folds = folds of Kerckring

  • = valvulae conniventes = two mucosal layers around a core of submucosa

• NORMAL FOLD THICKNESS

  @ jejunum	1.7 2.0 mm	>2.5 mm pathologic
  @ ileum	1.4 1.7 mm	>2.0 mm pathologic

P.794




• NORMAL NUMBER OF FOLDS

  @ jejunum	4 7/inch
  @ ileum	2 4/inch

• NORMAL FOLD HEIGHT

  @ jejunum	3.5 7.0 mm
  @ ileum	2.0 3.5 mm

• NORMAL LUMEN DIAMETER

  @ upper jejunum	3.0 4.0 cm	>4.5 cm pathologic
  @ lower jejunum	2.5 3.5 cm	>4.0 cm pathologic
  @ ileum	2.0 2.8 cm	>3.0 cm pathologic

• RULE OF 3's:

  • Wall thickness <3 mm

  • Valvulae conniventes <3 mm

  • Diameter <3 cm

  • Air-fluid levels <3

Normal Bowel Caliber

mnemonic:

3-6-9-12

3 cm	maximal size of small bowel <25 mm on CT
6 cm	maximal size of transverse colon
9 cm	maximal size of cecum
12 cm	maximal caliber of cecum before it may burst

Small Bowel Peristalsis

• INCREASED

  • Vagal stimulation

  • Acetylcholine

  • Anticholinesterase (eg, neostigmine)

  • Cholecystokinin

• DECREASED

  • Atropine (eg, Pro-Banthine )

  • Bilateral vagotomy

Intestinal function

Intestinal Gas

• INFLUX

  1. Aerophagia
  2. Liberation from intestinal tract
     1. neutralization of bicarbonate insecretions (CO₂)
     2. bacterial fermentation (CO₂, H₂, CH₄, H₂S)
  3. Diffusion from blood (N₂, O₂, CO₂)

  2 L
  
  8 L
  15 L

• EFFLUX

  1. Diffusion from intestines into bloodand expulsion from lung
  2. Expulsion from anus

  50 L
  2 L

Intestinal Fluid

• INFLUX

  1. Oral ingestion
  2. Intestinal secretions
     saliva
     bile
     gastric secretions
     pancreatic secretions
     intestinal secretions

  2.5 L
  8.2 L
  1.5 L
  0.5 L
  2.5 L
  0.7 L
  3.0 L

• EFFLUX

  1. Peranal
  2. Intestinal resorption (primarily in ileum+ ascending colon)

  10.6 L
  0.1 L

Intestinal Transit Time

(measured by pH telemetry); affected by type of diet

Small bowel transit time:	3 11 hours
Colonic transit time:	20 71 hours

Defecography/Evacuation Proctography

evacuation time	= 15 (range 5 40) seconds
anorectal angle	= angle formed between central axis of anal canal + line parallel to posterior wall of rectum 90 at rest and during voluntary contraction (squeeze maneuver) more obtuse during defecation straining (void)
anorectal junction	= point of taper of distal rectal ampulla as it merges with the anal canal; position of anorectal junction referenced to plane of ischial tuberosities = 0 3.5 cm; elevation during squeeze of 0 4.5 cm; elevation during void of 3.0 0 cm
rectovaginal space	= space between vagina and rectum
perineum	= area between external genital organs and anal verge
rectocele	= measurement of anteroposterior depth of convex wall protrusion extending beyond expected margin of normal rectal wall
	small	<2 cm;
	moderate	= 2 4 cm;
	large	>4 cm
peritoneocele	= extension of rectouterine excavation to below upper third of vagina; containing liquid/bowel/omentum
enterocele	= bowel present in peritoneocele
rectal prolapse	= descent of entire thickness of rectal wall through anal verge
rectal intussusception =	descent of the entire thickness of the rectal wall possibly extending into anal canal; starting 6 11 cm above anus; accompanied by formation of a circular indentation forming a ring pocket infolding of <3 mm in width/> 3 mm in width/intraluminal narrowing/descent into anal canal/external prolapse

Defecographic Measurements

P.795

Peritoneum

Ligaments and Peritoneal Spaces in Upper Abdomen

Peritoneal Spaces

• Definitions:

  Ligament	= formed by two folds of peritoneum supporting a structure within the peritoneal cavity
  Omentum	= specialized structure connecting stomach to an additional structure
  Mesentery	= two peritoneal folds connecting a portion of bowel to the retroperitoneum

• Embryology:

  • above transverse mesocolon:

    • RIGHT PERITONEAL SPACE

      • forms perihepatic space + lesser sac:

        • Right subphrenic space:

          • located between right hepatic lobe + diaphragm

          • limited posteriorly by right superior reflection of coronary lig. + right triangular ligament

        • Right subhepatic space:

          • divided into

            • anterior right subhepatic space: located just posterior to porta hepatis, communicating with lesser sac via epiploic foramen (= foramen of Winslow)

            • posterior right subhepatic space

              • = Morison pouch = hepatorenal fossa

              • Most dependent portion of the abdomen in supine patient!

        • Bare area of liver

          • situated between reflections of right + left coronary ligaments

          • continuous with right anterior pararenal space

        • Lesser sac:

          • superior recess:

            • surrounds medial aspect of caudate lobe

            • separated from splenic recess by gastropancreatic fold

          • splenic recess:

            • extends across midline to splenic hilum

          • inferior recess:

            • separates stomach from pancreas + transverse mesocolon

            • anteriorly covered by lesser omentum

        • Lesser omentum = combination of gastrohepatic ligament + hepatoduodenal ligament

        • Right triangular ligament:

          • forms from coalescence of superior and inferior reflections of right coronary ligament

          • divides posterior aspect of right perihepatic space into right subphrenic space + posterior right subhepatic space

    • LEFT PERITONEAL SPACE

      • forms left subphrenic space

        • Left subphrenic space:

          • artificially divided into

            • immediate subphrenic space:

              • between diaphragm + gastric fundus

            • perisplenic space:

              • bounded inferiorly by phrenicocolic lig.

            P.796

            
            

            • subhepatic space = gastrohepatic recess:

              • located between lateral segment of left hepatic lobe + stomach

          • separated from right subphrenic space by falciform ligament

        • Left triangular ligament:

          • forms from coalescence of superior and inferior reflections of left coronary ligament

          • located along superior aspect of left hepatic lobe

    • DORSAL MESENTERY gives rise to:

      • Gastrophrenic ligament

        • courses through immediate subphrenic space

        • suspends stomach from dome of diaphragm

      • Gastropancreatic ligament

        • formed by proximal left gastric artery

        • attaches posterior aspect of gastric fundus to retroperitoneum

        • partially separates superior recess of lesser sac from splenic recess

      • Phrenicocolic ligament

        • major suspensory ligament of spleen

        • attaches proximal descending colon to left hemidiaphragm

        • separates left subphrenic space from left paracolic gutter

      • Gastrosplenic ligament

        • remnant of dorsal mesentery

        • connects greater curvature of stomach with splenic hilum

        • contains short gastric vessels

      • Splenorenal ligament

        • connects posterior aspect of spleen to anterior pararenal space

        • contributes to left lateral + posterior border of lesser sac

        • encloses tail of pancreas + distal splenic artery + proximal splenic vein

      • Gastrocolic ligament

        • forms portion of anterior border of lesser sac

        • forms superior aspect of greater omentum

        • connects greater curvature of stomach with superior aspect of transverse colon

        • contains gastroepiploic vessels

    • VENTRAL MESENTERY gives rise to:

      • Falciform ligament

        • = sickle-shaped fold composed of two layers of peritoneum

        • attaches ventral surface of liver to anterior abdominal wall

        • its right layer continues into the superior layer of the coronary ligament, its left layer continues into the anterior layer of the left triangular ligament

        • contains ligamentum teres (= obliterated umbilical vein) in its free inferoposterior margin

        • continuous with fissure for ligamentum venosum

      • Gastrohepatic ligament:

        • arises in fissure of ligamentum venosum

        • connects medial aspect of liver to lesser curvature of stomach as part of lesser omentum

        • contains left gastric artery, coronary vein, lymph nodes

      • Hepatoduodenal ligament:

        • forms inferior edge of gastrohepatic ligament

        • forms anterior margin of epiploic foramen

        • extends from proximal duodenum to porta hepatis

        • contains common hepatic duct, common bile duct, hepatic artery, portal vein

  • below transverse mesocolon:

    • VENTRAL MESENTERY regresses

    • DORSAL MESENTERY forms:

      • Transverse mesocolon:

        • suspends transverse colon from retroperitoneum along anteroinferior edge of pancreas

        • forms posteroinferior border of lesser sac

        • contains middle colic vessels

      • Small bowel mesentery:

        • suspends small bowel from retroperitoneum

        • extends from ligament of Treitz to ileocecal valve

        • contains superior mesenteric vessels + lymph nodes

      • Sigmoid mesocolon:

        • attaches sigmoid colon to posterior pelvic wall

        • contains sigmoid + hemorrhoidal vessels

      • Greater omentum:

        • inferior continuation of gastrocolic ligament

        • formed by double reflection of dorsal mesogastrium thus composed of 4 layers of peritoneum

      • Superior + inferior ileocecal recesses:

        • located above + below terminal ileum

      • Retrocecal space:

        • present only if peritoneum reflects posterior to cecum

      • Right + left paracolic gutters:

        • located lateral to ascending + descending colon

      • Intersigmoid recess:

        • located along undersurface of sigmoid mesocolon

P.797

Gastrointestinal Disorders

Achalasia

• = failure of organized peristalsis + relaxation at level of lower esophageal sphincter

Etiology:

(a) idiopathic: abnormality of Auerbach plexus/medullary dorsal nucleus; neurotropic virus, gastrin hypersensitivity
(b) Chagas disease

• megaesophagus = dilatation of esophagus beginning in upper 1/3, ultimately entire length

• absence of primary peristalsis below level of cricopharyngeus

• nonperistaltic contractions

• bird-beak / rat tail deformity = V-shaped conical + symmetric tapering of stenotic segment with most marked narrowing at GE junction

• Hurst phenomenon = temporary transit through cardia when hydrostatic pressure of barium column is above tonic LES pressure

• sudden esophageal emptying after ingestion of carbonated beverage (eg, Coke)

• vigorous achalasia = numerous tertiary contractions in nondilated distal esophagus of early achalasia

• prompt relaxation of LES upon amyl nitrate inhalation (smooth-muscle relaxant)

CXR:

• right convex opacity behind right heart border; occasionally left convex opacity if thoracic aorta tortuous

• right convex opacity may be tethered by azygos arch allowing for greater dilatation above + below

• air-fluid level (stasis in thoracic esophagus filled with retained secretions + alimentary residue)

• small/absent gastric air bubble

• anterior displacement + bowing of trachea (LAT view)

• patchy bilateral alveolar opacities resembling acute/chronic aspiration pneumonia (M. fortuitum-chelonei infection)

Cx:	esophageal carcinoma in 2 7% (usually midesophagus)
Rx:	pneumatic dilatation/surgical myotomy
DDx:	(1) Neoplasm (separation of gastric fundus from diaphragm; normal peristalsis; asymmetric tapering) (2) Peptic stricture of esophagus

Secondary Achalasia

• = carcinoma of cardia/gastric fundus invading esophagus

  Age:

  >50 years

• duration of symptoms for <6 months

• irregular/asymmetric narrowing

• abrupt transition

• associated fundal lesion

Adenoma of Small Bowel

Location:

duodenum (21%), jejunum (36%), ileum (43%) esp. ileocecal valve

Histo:

• Hamartomatous polyp (77%), multiple in 47%, 1/3 of multiple lesions associated with Peutz-Jeghers syndrome

• adenomatous polyp (13%), may have malignant potential

• polypoid gastric heterotopic tumor (10%)

Adenomatous Colonic Polyp

• = EPITHELIAL POLYP

• Most common benign colonic tumor (68 79%)

Predisposed:	previously detected polyp/cancer; family history of polyps/cancer; idiopathic inflammatory bowel disease; Peutz-Jeghers syndrome; Gardner syndrome; familial polyposis
Prevalence:	3% in 3rd decade; 10% in 7th decade; 26% in 9th decade
Location:	rectum (21 34%); sigmoid (26 38%); descending colon (6 18%); transverse colon (12 13%); ascending colon (9 12%); multiple in 35 50% (usually <5 10 in number)

Histo:

• Tubular adenoma (75%)

  • = cylindrical glandular formation lined by stratified columnar epithelium + containing nests of epithelium within lamina propria

  • usually <10 mm in diameter

  • often pedunculated if >10 mm

  malignant potential:

  <10 mm in 1%; 10 20 mm in 10%; >20 mm in 35%

• Tubulovillous adenoma (15%)

  • = mixture between tubular + villous adenoma

  malignant potential:

  <10 mm in 4%; 10 20 mm in 7%; >20 mm in 46%

• Villous adenoma (10%)

  • = thin frondlike surface projections ( villous fronds )

  • potassium depletion

  • often >20 mm in diameter with papillary surface

  • often broad-based sessile lesion

  malignant potential:

  <10 mm in 10%; 10 20 mm in 10%; >20 mm in 53%

Adenoma size & incidence of malignancy:

• <5 mm in 0.5%; 5 9 mm in 1%; 10 20 mm in 5 10% >20 mm in 10 50% malignant

• Invasive carcinoma (= penetration of muscularis mucosa):

  • rare in a pedunculated adenoma of <15 mm

  • in 30% of villous adenomas of >50 mm

• All polyps >10 mm should be removed!

• Time for adenoma-carcinoma sequence probably averages 10 15 years!

Probability of coexistent colonic growth:

• synchronous adenoma in 50%

• metachronous adenoma in 30 40%

• synchronous adenocarcinoma in 1.5 5%

• metachronous adenocarcinoma in 5 10%

• asymptomatic (75%)

• diarrhea, abdominal pain

• peranal hemorrhage (67%)

• Colonoscopy (incomplete in 16 43%)

BE:

Sensitivity of DCBE in detecting polyps:

• <10 mm 80 83%; >10 mm 96 97%; all 84 88%; rate of detection of polyps <10 mm higher with DCBE than SCBE

  P.798

  
  

  • sessile flat/round polyp

  • pedunculated polyp: stalk >2 cm in length almost always indicative of a benign polyp

  • suggestive of malignancy: irregular lobulated surface, broad base = width of the base greater than height, retraction of colonic wall = dimpling/indentation/puckering at base of tumor, interval growth

  • lacelike/reticular surface pattern CHARACTERISTIC for villous adenoma (occasionally in tubular adenoma)

DDx:

(1) Nonneoplastic: hyperplastic polyp, inflammatory pseudopolyp, lymphoid tissue, ameboma, tuberculoma, foreign-body granuloma, malacoplakia, heterotopia, hamartoma
(2) Neoplastic subepithelial: lipoma, leiomyoma, neurofibroma, hemangioma, lymphangioma, endothelioma, myeloblastoma, sarcoma, lymphoma, enteric cyst, duplication, varix, pneumatosis, hematoma, endometriosis

Adenocarcinoma of Small Bowel

Frequency:	35% of primary malignant neoplasms of small bowel; about 50 less common than colonic carcinoma Most common primary malignancy of small bowel
Risk factors:	familial adenomatous polyposis (FAP), Crohn disease, sprue, Peutz-Jeghers syndrome, hereditary nonpolyposis colon cancer syndrome (Lynch syndrome), congenital bowel duplication, ileostomy, duodenal/jejunal bypass surgery
Histo:	mostly moderately to well differentiated; may arise in villous tumors/de novo; no correlation between size and invasiveness

• vague mild abdominal pain

• anemia, weight loss

• nausea, vomiting, anorexia

Location:

duodenum (54%, especially near ampulla), jejunum (28%) > ileum (18%)
in FAP: duodenum
in celiac disease: jejunum
in Crohn disease: ileum

• annular stricture with overhanging edges (60%)

• lobulated/ovoid polypoid sessile mass (41%)

• Duodenal tumors tend to be papillary/polypoid!

• ulcerated mass (27%)

CT:

• soft-tissue mass with heterogeneous attenuation

• moderate contrast enhancement

Cx:	intussusception
Prognosis:	poor (often disseminated at time of presentation); 30% 5-year survival rate
DDx:	lymphoma (lymphadenopathy more bulky)

Afferent Loop Syndrome

• = PROXIMAL LOOP/BLIND LOOP SYNDROME

• = partial intermittent obstruction of afferent loop leading to overdistension of loop by gastric juices after Billroth-II gastrojejunostomy

Cause:

gastrojejunostomy with left-to-right anastomosis (= proximal jejunal loop attached to greater curvature instead of lesser curvature), mechanical factors (intussusception, adhesion, kinking), inflammatory disease, neoplastic infiltration of local mesentery or anastomosis, idiopathic motor dysfunction

• postprandial epigastric fullness relieved by bilious vomiting

• vitamin B₁₂ deficiency with megaloblastic anemia

• afferent loop with abnormal bacterial flora (Gram negative, resembling colon in quality + quantity)

Abdominal plain film:

• normal in 85% (no air in lumen of afferent loop)

UGI:

• preferential emptying of stomach into proximal loop

• proximal loop stasis

• regurgitation

CT:

• rounded water-density masses adjacent to head + tail of pancreas forming a U-shaped loop

• oral contrast material may not enter loop

• may result in biliary obstruction (increased pressure at ampulla)

Rx:

antibiotic therapy

Aids

• Gastrointestinal involvement due to opportunistic infections + AIDS-associated neoplasms!

• Pathologic abnormalities at multiple sites with single/several opportunistic organisms are frequent!

• A. VIRAL PATHOGENS

  • Cytomegalovirus infection

    • Most common cause of life-threatening opportunistic viral infection in AIDS patients!

      Organism:	double-stranded DNA virus of the herpes family
      Infection:	ubiquitous among humans occurring at an early age in populations with poor sanitation + crowded living conditions

    • Result of reactivation of latent virus in previously infected host!

      Prevalence:	13% of all gastrointestinal diseases in AIDS patients
      Path:	infection of endothelial cells leads to small vessel vasculitis resulting in hemorrhage, ischemic necrosis, ulceration
      Histo:	large mononuclear epithelial/endothelial cells that contain intranuclear/cytoplasmatic inclusions with surrounding inflammation
      Location:	colon > small bowel (terminal ileum) > esophagus > stomach

    • @ Esophagus

      • single/multiple large superficial ulcers

    • @ Small bowel

      • luminal narrowing secondary to marked bowel wall thickening

      • thickened irregular folds (vasculitis leading to thrombosis + ischemia)

      • penetrating ulcer perforation

      • CMV pseudotumor (uncommon)

    P.799

    
    

    • @ Colon (CMV colitis)

      • hematochezia, crampy abdominal pain, fever

      • findings of toxic megacolon

      • discrete small well-defined nodules (similar to lymphoid nodular hyperplasia) throughout entire colon

      • aphthous ulcers on background of normal mucosa

      • marked bowel wall thickening

      • double-ring/target sign on CT (due to increased submucosal edema)

      • ascites

      • inflammation of pericolonic fat + fascia

      Rx:

      ganciclovir (effective in 75%)

  • Herpes simplex virus infection

    • Result of reactivation of latent virus in previously infected host

      Organism:	neurotropic DNA virus of herpes family
      Prevalence:	70% for type 1, 16% for type 2 (endemic in United States); type 2 much more common in AIDS
      Infection:	direct inoculation through mucous membrane contact; from dormant state in root ganglia reactivated + transported via efferent nerves to mucocutaneous surface
      Location:	oral cavity, esophagus, rectum, anus

    • multiple small discrete ulcers

  • HIV infection

    • Not an AIDS-defining illness!

      Infection:

      acute HIV-infection with transient immunosuppression/during AIDS

    • >2-cm large solitary ulcer in the mid- or distal esophagus (HIV-infected cells cause alterations in cytokines resulting in infiltration of inflammatory cells into submucosa + destruction of mucosa)

    Rx:

    corticosteroids

• B. FUNGAL PATHOGENS

  • Candidiasis

    • The absence of thrush does not exclude the diagnosis of candida esophagitis!

      Organism:	commensal fungus Candida albicans
      Prevalence:	10 20% (in United States); up to 80% in developing countries
      Location:	oral cavity, esophagus

    • discrete linear/irregular longitudinally oriented filling defects in esophagus

    Cx:

    disseminated systemic candidiasis (rare + indicative of granulocytopenia from chemotherapy/direct inoculation via catheter)

  • Histoplasmosis

    Organism:	dimorphic opportunistic fungus
    Prevalence:	10% GI involvement with disseminated histoplasmosis in AIDS patients
    Location:	colon > terminal ileum

    • segmental inflammation/apple core lesion/bowel stricture

    • hepatosplenomegaly

    • mesenteric lymphadenopathy

    • diffuse hypoattenuation of spleen

• C. PROTOZOAN PATHOGENS

  • Cryptosporidiosis

    • One of the most common causes of enteric + biliary disease in AIDS patients!

      Organism:	intracellular parasite Cryptosporidium
      Prevalence:	isolated in 6% of all patients with AIDS; in 16% (in United States) + in up to 48% (in developing countries) in patients with diarrhea

    • severe choleralike debilitating diarrhea with fluid loss of 10-17 L/day

      Location:

      jejunum > other small bowel > stomach > colon

    • Cryptosporidium antritis (= area of focal gastric thickening + ulceration)

    • small bowel dilatation (increased secretions)

    • regular fold thickening + effacement (atrophy, blunting, fusion, loss of villi)

    • toothpaste appearance of small bowel (mimicking sprue)

    • dilution of barium (hypersecretion)

    • marked antral narrowing (extensive inflammation)

    • AIDS-related cholangitis

    Dx:

    microscopic identification in stool/biopsy

  • Pneumocystosis

    • Likely to occur in patients treated with aerosolized pentamidine!

      Organism:	eukaryotic microbe Pneumocystis carinii
      Prevalence:	pulmonary infection in 75% of AIDS
      patients;	in <1% dissemination
      Location:	liver, spleen, lymph nodes

    • hepatic + splenic + nodal punctate calcifications

    • multiple tiny echogenic foci in spleen

    • multiple low-attenuation lesions of varying size in spleen (foamy eosinophilic material) with subsequently progressive rimlike/punctate calcifications

• D. BACTERIAL PATHOGENS

• 1. tuberculosis

  • Most common cause of serious HIV-related infection worldwide with tendency to occur earlier than other AIDS-defining opportunistic infections!

    Prevalence:	4% (in United States) + 43% (in developing countries) of HIV-infected persons
    Infection:	swallowing of infected sputum; hematogenous spread from pulmonary focus; direct extension from lymph node
    Location:	lymph nodes, liver, spleen, peritoneum, GI tract (especially ileum, colon, ileocecal valve)

  • low-attenuation mesenteric lymphadenopathy (suggestive of necrosis)

  • segmental ulceration

  • inflammatory stricture

  • hypertrophic lesion resembling polyp or mass

• 2.Mycobacterium avium complex infection

  • = PSEUDO-WHIPPLE DISEASE in AIDS

  • Most common opportunistic infection of bacterial origin in AIDS patients!

  P.800

  
  

  • Most common nontuberculous mycobacterial infection in AIDS patients!

    Organism:	facultative intracellular acid-fast bacillus M. avium/M. intracellulare
    Infection:	invasion of Peyer patches + adjacent mesenteric lymph nodes
    Histo:	true granulomas with Langhans giant cells and caseous necrosis are rare because infection occurs in patients with advanced disease and a CD4 cell count of <100/ L

  • diarrhea, malabsorption (similar clinical picture as in Whipple disease caused by Mycobacterium avium-intracellulare)

    Location:

    jejunum (most common)

  • mild dilatation of middle + distal small bowel

  • wall thickening of small bowel loops

  • diffuse irregular mucosal fold thickening and nodularity without ulceration

  • mesenteric + retroperitoneal lymphadenopathy (1.0 1.5 cm in size) with homogeneous soft-tissue attenuation causing segmental separation of small bowel loops

  • hepatosplenomegaly

  • multiple tiny echogenic foci in liver + spleen (occasionally large hypoechoic/low-attenuation lesions)

  Dx:	(1) Visualization of large numbers of intracellular acid-fast bacilli in foamy histiocytes of tissue specimens (2) Tissue culture
  DDx:	Whipple disease (positive with periodic acid-Schiff stain just like M. avium, but not with acid-fast stain, responsive to tetracyclines)

• E. OTHER INFECTIONS

  • Bacillary angiomatosis

    Organism:	Rickettsiales Bartonella henselae
    Histo:	characteristic pattern of vascular proliferation with bacilli
    Location:	cutis (mimicking Kaposi sarcoma), liver, spleen, lymph nodes

    • peliosis (blood-filled cystic spaces) of liver/spleen

    • abdominal lymphadenopathy with contrast enhancement

  • Isospora belli

    • Infection resembles cryptosporidiosis

      Organism:	protozoan pathogen
      Histo:	oval oocysts within bowel lumen/epithelial cells; localized inflammation; fold atrophy
      Location:	small intestine

    • severe watery diarrhea

    • fold thickening

• F. AIDS-ASSOCIATED NEOPLASMS

  • Kaposi sarcoma

  • Non-Hodgkin lymphoma

    • 2nd most common AIDS-associated neoplasm

      Prevalence:	in 4 10% of AIDS patients (60 times higher risk compared with general population); occurs in all AIDS risk groups
      Histo:	multiclonal B-cell lymphoma of high or intermediate grade

    • at initial presentation widely disseminated disease often with extranodal involvement

      Location:

      CNS, bone marrow, GI tract (stomach, small bowel)

  • @ Stomach

    • circumferential/focal wall thickening

    • mural mass ulceration

  • @ Small bowel

    • diffuse/focal wall thickening

    • excavated mass

    • solitary/multiple liver lesions

Differential diagnostic considerations:

• Splenomegaly (31 45%)

  Cause:

  nonspecific (most), lymphoma, infection (M. avium-intracellulare, P. carinii)

• Lymphadenopathy (21 60%)

  Cause:	reactive hyperplasia (most), Kaposi sarcoma, lymphoma, infections
  Size:	<3 cm in diameter (in 95%)

• Hepatomegaly (20%)

  Cause:

  nonspecific, hepatitis, fatty infiltration, lymphoma, Kaposi sarcoma

• AIDS-related cholangiopathy:

  Organism:

  CMV, Cryptosporidium

  • papillary stenosis of CBD

  • dilatation of extra- and intrahepatic bile ducts

  • periductal fibrosis

  • strictures + irregularities of bile ducts resembling primary sclerosing cholangitis

  • intraluminal polypoid filling defects

• AIDS-related esophagitis:

  Organism:

  Candida, herpes simplex, CMV

  • giant esophageal ulcer: HIV (76%), CMV (14%)

  • esophageal fistula/perforation: tuberculosis, actinomycosis

• Gastritis

  Organism:

  CMV (GE junction + prepyloric antrum), Cryptosporidium (antrum)

• AIDS enteritis

  Organism:

  Cryptosporidium, M. avium complex

• AIDS colitis

  • ischemic bowel

  • acute appendicitis

  • neutropenic colitis

  • pseudomembranous colitis

  • infectious colitis/ileitis

• Bowel obstruction

  • infection

  • intussusception: Kaposi sarcoma, lymphoma

Amebiasis

• = primary infection of the colon by protozoan Entamoeba histolytica

Countries:	worldwide distribution, most common in warm climates; South Africa, Egypt, India, Asia, Central + South America (20%); United States (5%)
Route:	contaminated food/water (human cyst carriers); cyst dissolves in small bowel; trophozoites settle in colon; proteolytic enzymes + hyaluronidase lyse intestinal epithelium; may embolize into portal venous + systemic blood system
Histo:	amebic invasion of mucosa + submucosa causing tiny ulcers, which spread beneath mucosa + merge into larger areas of necrosis; mucosal sloughing; secondary bacterial infection

P.801

• asymptomatic for months/years

• acute attacks of diarrhea (loose mucoid bloodstained stools)

• fever, headache, nausea

  Location:

  (areas of relative stasis) right colon + cecum (90%) > hepatic + splenic flexures > rectosigmoid

• loss of normal haustral pattern with granular appearance (edema, punctate ulcers)

• collarbutton ulcers

• cone-shaped cecum

• several cm long stenosis of bowel lumen in transverse colon, sigmoid colon, flexures (result of healing + fibrosis); in multiple segments

• ameboma = hyperplastic granuloma with bacterial invasion of amebic abscess; usually annular + constricting/intramural mass/cavity continuous with bowel lumen; shrinkage under therapy in 3 4 weeks

• ileocecal valve thickened + fixed in open position with reflux

• involvement of distal ileum (10%)

Dx:	stool examination/rectal biopsy
Cx:	(1) Toxic megacolon with perforation (2) Amebic abscess in liver (2%), brain, lung (transdiaphragmatic spread of infection), pericolic, ischiorectal, subphrenic space (3) Intussusception in children (due to ameboma) (4) Fistula formation (colovesical, rectovesical, rectovaginal, enterocolic)

Amyloidosis

• = group of heterogeneous disorders caused by interstitial deposits of a protein-polysaccharide in various organs leading to hypoxia, mucosal edema, hemorrhage, ulceration, mucosal atrophy, muscle atrophy

Cause:	(a) prolonged antigenic stimulation of RES by chronic infection (b) disorder of immunoincompetence (c) aging (d) idiopathic
Histo:	amorphous eosinophilic hyaline material deposited around terminal blood vessels, stains with Congo red + crystal violet; green birefringence under polarizing light; amyloid fibrils have -pleated sheet structure (= fibrilloses)

Biochemical classification (1979):

• AL amyloidosis

  • (A = amyloidosis, L = light chain immunoglobulin)

  • monoclonal protein in serum + urine

  • occurs in primary amyloidosis + myeloma-associated amyloidosis

    Histo:

    massive deposits in muscularis mucosae + submucosa

  • thickening of folds with polyps/large nodules

• SAA amyloidosis (S = serum, AA = amyloid A)

  • occurs in secondary = reactive amyloidosis

    Histo:

    expansion of lamina propria

  • coarse mucosal pattern + innumerable fine granular elevations

• AF amyloidosis (A = amyloid, F = familial)

  • AF prealbumin as precursor of fibrils

  • occurs in familial amyloidosis

• AS amyloidosis (A = amyloid, S = senile)

  • AS prealbumin as precursor of fibrils

  • occurs in senile amyloidosis

  • massive amyloid deposition

• AH amyloidosis (A = amyloid, H = hemodialysis)

  • ₂ microglobulin as precursor of fibrils

• AE amyloidosis (A = amyloid, E = endocrine)

  • calcitonin produced by medullary thyroid carcinoma is precursor of fibrils

Reimann classification (1935):

• Primary = idiopathic amyloidosis

  • = probably autosomal dominant inheritance with immunologically determined dysfunction of plasma cells

  • absence of discernible preceding/concurrent disease

  Location:

  (predominant involvement of connective tissues + mesenchymal organs) heart (90%), lung (30 70%), liver (35%), spleen (40%), kidneys (35%), adrenals, tongue (40%), GI tract (70%), skin + subcutis (25%)

  • tendency to nodular deposition

• 2.Secondary amyloidosis (most common form)

  • following/coexistent with prolonged infectious/inflammatory processes

    Cause:	rheumatoid arthritis (in 20%), Still disease, tuberculosis, osteomyelitis, leprosy, chronic pyelonephritis, bronchiectasis, ulcerative colitis, Waldenstr m macro-globulinemia, familial Mediterranean fever, lymphoreticular malignancy, paraplegia
    Location:	spleen, liver, kidneys (>80%), breast, tongue, GI tract, connective tissue

  • small amyloid deposits

• 3.Amyloidosis associated with multiple myeloma

  • may precede development of multiple myeloma

    Incidence:

    10 15%

  • primary amyloidosis with osteolytic lesions in myelomatous disease

• 4.Tumor-forming/organ-limited amyloidosis

  • related to primary type

  • (a) hereditary = familial amyloidosis

  • (b) senile amyloidosis (limited to heart/brain/pancreas/spleen)

  • large localized masses

• GI involvement in primary more common than in secondary amyloidosis!

• malabsorption (diarrhea, protein loss)

• occult GI bleeding

• obstruction

• macroglossia

• @ Esophagus (11%)

  • loss of peristalsis

  P.802

  
  

  • megaesophagus

• @ Stomach (37%)

  • postprandial epigastric pain + heartburn

  • acute erosive hemorrhagic gastritis

  • (a) diffuse infiltrative form

    • small-sized stomach with rigidity + loss of distensibility simulating linitis plastica (from thickening of gastric wall)

    • effaced rugal pattern

    • diminished/absent peristalsis

    • marked retention of food

  • (b) localized infiltration (often located in antrum)

    • irregularly narrowed + rigid antrum

    • thickened rugae

    • superficial erosions/ulcerations

  • (c) amyloidoma = well-defined submucosal mass

• @ Small bowel (74%)

  • diffuse form (more common)

    • diffuse uniform thickening of valvulae conniventes in entire small bowel

    • broadened flat undulated mucosal folds (mucosal atrophy)

    • jejunalization of ileum

    • impaired intestinal motility

    • small bowel dilatation

  • localized form (less common)

    • multiple pea-/marble-sized deposits

    • pseudoobstruction = physical + plain-film findings suggesting mechanical obstruction with patent large + small bowel on barium examination (involvement of myenteric plexus)

  Cx:

  small bowel infarction

• @ Colon (27%):

  • pseudopolyps in colon

• @ Bone:

  • bone cysts

• @ Liver:

  Path:

  extracellular deposition of amyloid in the spaces of Disse (= narrow gaps between endothelial linings of sinusoids and hepatocytes of hepatic lamina) with progressive encroachment on hepatic parenchymal cells + sinusoids

  • hepatic function usually preserved

  CT:

  • hepatomegaly

  • regions of low attenuation with decreased contrast enhancement

• @ Spleen:

  Histo:

  (a) nodular form involving lymph follicles
  (b) diffuse form infiltrating red pulp

  • discrete masses

  • splenomegaly (4 13%)

  MR:

  • T2 values significantly lower than normal

Cx:	spontaneous splenic rupture (from vascular fragility + acquired coagulopathy)
Dx:	by rectal/gingival biopsy
DDx:	Whipple disease, intestinal lymphangiectasia, lymphosarcoma

Angiodysplasia of Colon

• = VASCULAR ECTASIA = ARTERIOVENOUS MALFORMATION (not a true AVM)

  Cause:	age-related degenerative dilatation of normal vessels in submucosa of bowel wall
  Theory:	colonic contractions result in dilatation of colonic veins, venules and capillaries forging multiple small arteriovenous communications
  Associated with:	aortic stenosis (20%); NOT related to extraintestinal angiomatous lesions
  Prevalence:	most common vascular lesion of GI tract!
  at autopsy:	2%
  at colonoscopy:	0.8% (age >50 years)
  Age:	majority > 55 years; M = F
  Location:	(a) cecum + ascending colon (74%) (b) jejunum, ileum (15%) (c) descending + sigmoid colon ( 25%)
  Site:	usually at antimesenteric border

• chronic intermittent low-grade bleeding

• occasionally massive bleeding

NUC (Tc-99m labeled RBCs):

• focus of tracer accumulation at site of bowel hemorrhage migrating with peristalsis

BE:

• no abnormality (due to soft submucosal lesion)

NUC:

• increased tracer accumulation of Tc-99m labeled RBC

Angio:

• arterial tuft = cluster/tangle of vessels during arterial phase along antimesenteric border

• early opacification of draining ileocolic vein

• densely opacified dilated tortuous ileocolic vein into late venous phase

• contrast extravasation into bowel lumen (unusual)

Rx:

surgical excision

Anisakiasis

• = parasitic disease of GI tract

  Cause:	ingestion of Anisakis larvae present in raw/undercooked fish (mackerel, cod, pollack, herring, whiting, bonito, squid) consumed as sashimi, sushi, ceviche, lomi-lomi
  Organism:	worm with straight/serpentine/circular threadlike appearance

• Site of penetration by larvae determines clinical form!

• @ Gastric anisakiasis

  • acute gastric pain, nausea, vomiting a few hours after ingestion (DDx: acute gastritis, peptic ulcer, food poisoning, neoplasia)

  • eosinophilia

  • mucosal edema

  • about 3-cm-long threadlike filling defects (= larvae)

• @ Intestinal anisakiasis

  • diffuse abdominal tenderness/colicky abdominal pain, nausea, vomiting (DDx: acute appendicitis, regional enteritis, intussusception, ileus, diverticulitis, neoplasia)

  • leukocytosis without eosinophilia (frequent)

    Histo:

    marked edema, eosinophilic infiltrates, granuloma formation

  • thickened folds

  P.803

  
  

  • disappearance of Kerckring folds

  • thumbprinting/saw-tooth appearance

  • irregular luminal narrowing

  • eosinophilic ascites (DDx: eosinophilic gastroenteritis, hypereosinophilic syndrome)

    Cx:

    ileus

• @ Colonic anisakiasis (rare)

  DDx:

  colonic tumor

Anorectal Malformation

• Rectal atresia

  • = open anus + atretic rectal segment superior to anus + no fistula

• Ectopic anus

  • = fistulous opening of bowel due to failure of terminal bowel to descend normally

    Site of arrest:

    high/low colon arrest = above/below puborectal sling

  • most common anomaly of anorectal segment

  • anal dimple + external sphincter in normal position

    Location of fistula:

    perineum, vestibule, vagina, urethra, bladder, cloaca

  • low small bowel/colonic obstruction

  • M line accurately represents level of puborectal muscle = line drawn horizontally through junction of lower 1/3 + upper 2/3 of ischium on lateral radiograph

• Imperforate anus

  • = blind ending of terminal bowel + no fistula

• Cloacal malformation

• Cloacal exstrophy

Embryology:

• during weeks 3 and 4 the dorsal part of the yolk sac folds are incorporated into embryo forming the primitive hindgut consisting of distal part of transverse + descending + sigmoid colon, rectum, superior portion of anal canal, epithelium of urinary bladder, and most of the urethra; at 4 weeks the transverse rectovesical septum descends caudally between allantois and hindgut dividing the cloaca into urogenital sinus ventrally + anorectal canal dorsally; by 7th week the rectovaginal septum fuses with cloacal membrane creating a urogenital membrane ventrally + anal membrane dorsally; perineum is formed by fusion of rectovesical septum + cloacal membrane; anal membrane ruptures by 9th week

In 48% associated with:

(part of VACTERL syndrome)

• GU anomalies (20%):

  • renal agenesis/ectopia, vesicoureteral reflux, obstruction, hypospadia (3.1%); M > F

• Lumbosacral segmentation anomalies (30%):

  • dysplasia, agenesis, hemivertebrae

• GI anomalies (11%):

  • esophageal atresia tracheoesophageal fistula (4%), duodenal atresia/stenosis

• Cardiovascular anomalies (8%)

• Abdominal wall (2%)

• Cleft lip cleft palate (1.6%)

• Down syndrome (1.5%)

• Meningomyelocele (0.5%) + occult myelodysplasia

• Others (8%)

Antral Mucosal Diaphragm

• = ANTRAL WEB

  Age range:	3 months to 80 years
  Associated with:	gastric ulcer (30 50%)

• symptomatic if opening <1 cm

  Location:

  usually 1.5 cm from pylorus (range 0 7 cm)

• constant symmetric band of 2 3 mm thickness traversing the antrum perpendicular to long axis of stomach

• double bulb appearance (in profile)

• concentric/eccentric orifice

• normal peristaltic activity

Appendicitis

Prevalence:	1 4% in children with acute abdominal pain
Lifetime risk:	7 9% in Western world population
Etiology:	obstruction of appendiceal lumen by lymphoid hyperplasia (60%), fecolith (33%), foreign bodies (4%), stricture, tumor, parasite; Crohn disease (in 25%)
Cause:	luminal obstruction from

• fecolith (11 52%) = hard crushable concretions from inspissation of fecal material + inorganic salts

• appendiceal calculus = hard noncrushable calcified stone (7 15%)

• lymphoid hyperplasia

• foreign body

• parasite

• primary tumor: carcinoid, adenocarcinoma, Kaposi sarcoma, lymphoma

• metastatic tumor: colon cancer, breast cancer

Pathogenesis:

• continued secretion of mucus in appendiceal obstruction elevates intraluminal pressure + distends lumen; venous engorgement + arterial compromise + tissue ischemia ensues after intraluminal pressure exceeds capillary perfusion pressure

Peak age:

2nd decade; thereafter declining incidence; M:F = 3:2 (in teens/young adults, thereafter 1:1)
Rare under the age of 2 years!

• 80% clinical accuracy (78 92% in males, 58 85% in females):

  Diagnostic dilemma (20 35%):

  • in elderly, ovulating women, infants/young children

  • 32 45% rate of misdiagnosis in women between ages 20 40!

  • 5 25% false-negative appendectomy rate for pediatric population!

• pain

  • mild poorly localized visceral pain of 4 6 hours duration referred to epigastrium + periumbilical region

  • crampy pain migrates into RLQ pain over appendix = McBurney sign (72%) and becomes continuous + more severe (somatic pain)

• anorexia, nausea, vomiting (40%)

• afebrile/low-grade fever (56%)

  • Suspect perforation with temperature >38.3

• leukocytosis with left shift (88%)

Clinical scoring system:	MANTRELS score of 10
Migration of pain to RLQ	1
Anorexia	1
Nausea and vomiting	1
Tenderness in RLQ	2
Rebound pain	1
Elevated temperature	1
Leukocytosis	2
Shift of WBC count to left	1

P.804

Location:

• base of appendix: posteromedial wall of cecum + 3 cm below ileocecal valve

  • The appendix is on the same side of the cecum as the ileocecal valve!

• tip of appendix: retrocecal, subcecal, retroileal, preileal, within pelvis (30%), extraperitoneal (5%)

Abdominal plain film (abnormalities seen in <50%):

• Plain-film findings become more distinctive after perforation, while clinical findings subside/simulate other diseases!

• usually laminated calcified appendicolith in RLQ (in 7 15%):

  • Appendicolith + abdominal pain = 90% probability of acute appendicitis!

  • Appendicolith in acute appendicitis means a high probability for gangrene/perforation!

• cecal changes:

  • thickening of cecal wall

  • water-density mass + paucity/absence of intestinal gas in RLQ (in 24% of perforations)

  • cecal ileus = gas-fluid level in cecum in gangrene (= local paralysis)

  • colon cutoff sign = amputation of gas at the hepatic flexure (in 20% of perforations) due to spastic ascending colon

• small bowel obstruction pattern = small bowel dilatation with air-fluid levels (in 43% of perforations)

• extraluminal gas (in 33% of perforations):

  • gas loculation

  • mottled bacteriogenic gas

  • pneumoperitoneum (rare)

• loss of fat planes:

  • focal increase in thickness of lateral abdominal wall in 32% (= edema between properitoneal fat line + cecum)

  • loss of properitoneal fat line

  • loss of pelvic fat planes around the bladder/right obturator (= fluid/pus in cul-de-sac)

  • loss of definition of right inferior hepatic outline (= free peritoneal fluid)

  • distortion of psoas margin + flank stripes

• scoliosis (due to muscle irritation)

BE/UGI (accuracy 50 84%):

• failure to fill appendix with barium (normal finding in up to 35%)

• indentation along medial wall of cecum (= edema at base of appendix/matted omentum/periappendiceal abscess)

Graded-compression US (85% sensitive, 92% specific, 78 96% accurate, 91 94% PPV, 89 97% NPV):

• Nondiagnostic study in 4% due to inadequate compression of RLQ

• Useful in ovulating women (false-negative appendectomy rate in males 15%, in females 35%) + infants/children

• visualization of noncompressible appendix as a blind-ending tubular aperistaltic structure (seen only in 2% of normal adults, but in 50% of normal children)

• laminated wall with target appearance of 6 mm in total diameter on cross section (81% SPECIFIC)/mural wall thickness 2 mm

• lumen may be distended with anechoic/hyperechoic material

• pericecal/periappendiceal fluid

• increased periappendiceal echogenicity (= infiltration of mesoappendix/pericecal fat)

• enlarged mesenteric lymph nodes

• loss of wall layers = gangrenous appendix

• perforated appendix (23 73%):

  • loss of echogenic submucosal layer

  • appendix no longer visualized (40 60%)

  • loculated periappendiceal/pelvic fluid collection gas bubbles (= abscess)

  • prominent hyperechoic mesoappendix/pericecal fat

  • visualization of appendicolith (6%) = bright echogenic focus with clean distal acoustic shadowing

  • gas bubbles localized to perforation site

• hypoechoic zones with poor margination within inflamed fat (= phlegmonous appendicitis)

• sympathetic thickening of adjacent terminal ileum + ascending colon

False-negative US:

• failure to visualize appendix

  • inability of adequate compression

  • aberrant location of appendix (eg, retrocecal)

  • appendiceal perforation

• early inflammation limited to appendiceal tip

False-positive US:

• normal appendix mistaken for appendicitis

• alternate diagnosis: Crohn disease, pelvic inflammatory disease, inflamed Meckel diverticulum

• spontaneous resolution of acute appendicitis

Color Doppler US:

• increased conspicuity (= increase in size + number) of circumferential vessels in and around the wall of the appendix (= hyperemia)

• decreased resistance of arterial waveforms

• continuous/pulsatile venous flow

• decreased/no perfusion = gangrenous appendicitis

CT (87 100% sensitive, 89 98% specific, 93 98% accurate, 92 98% PPV, 95 100% NPV):

• normal appendix visualized in 67 100%:

  • 1 2 cm below ileocecal junction from posteromedial aspect of cecum with a diameter of up to 10 mm

• abnormal appendix:

  • distended lumen (appendix >7 mm in diameter)

  • circumferential wall thickening

  • homogeneously enhancing wall mural stratification ( target sign )

  • appendicolith = homogeneous/ringlike calcification (25%)

  • distal appendicitis = abnormal tip of appendix + normal proximal appendix and normal cecal apex

• periappendicular inflammation (98%):

  • linear streaky densities in periappendicular/pericecal/mesenteric/pelvic fat

  • subtle clouding of mesentery

  • local fascial thickening

  P.805

  
  

  • free peritoneal fluid

  • mesenteric lymphadenopathy

  • marked terminal ileal wall thickening

  • localized lymphadenopathy

  • peritonitis

  • small-bowel obstruction

• circumferential/focal cecal apical thickening (80%):

  • arrowhead sign = funnel of contrast medium in cecum symmetrically centering about occluded orifice of appendix (30% sensitive, 100% specific)

• perforated appendix:

  • defect in the enhancing appendiceal wall

  • nonvisualization of appendix (due to fragmentation)

  • phlegmon = diffuse substantial inflammation of periappendiceal fat with ill-defined fluid collections(DDx: ileocolitis with secondary inflammation of appendix)

  • pericecal/mesenteric/interloop/pelvic abscess = poorly encapsulated single/multiple fluid collection with air/extravasated contrast material

  • extraluminal appendicolith

  • extraluminal air

False-negative CT:

• overlapping range in maximal appendiceal diameter between inflamed + uninflamed appendix

• appendix mistaken for unopacified bowel

• inflammation limited to appendiceal tip

Prognosis:

• mild acute appendicitis may resolve spontaneously (after relief of inciting obstruction)

• recurrent appendicitis (10%) = repeated similar episodic attacks of RLQ pain leading to appendectomy + showing acute inflammation

• chronic appendicitis (1%) = RLQ pain of >3 weeks + no alternative diagnosis + chronic active inflammation on histology + relief of symptoms after appendectomy

• Mortality rate of 1% (associated with perforation)

Cx:	perforation (13 30 73%), abscess formation, peritonitis, wound infection, sepsis, infertility, adhesions, bowel obstruction, death
Rx:	finding of appendicolith is sufficient evidence to perform prophylactic appendectomy in asymptomatic patients (50% have perforation/abscess formation at surgery)
DDx:	colitis, diverticulitis, epiploic appendagitis, small bowel obstruction, infectious enteritis, duodenal ulcer, pancreatitis, intussusception, Crohn disease, mesenteric lymphadenitis, ovarian torsion, pelvic inflammatory disease; primary neoplasm of appendix Only 22 38% of children referred for suspected appendicitis actually have appendicitis

Ascariasis

• = most common parasitic infection in world; cosmopolitan occurrence; endemic along Gulf Coast, Ozark Mountains, Nigeria, Southeast Asia

Organism:	Ascaris lumbricoides = roundworm parasite, 15 35 cm in length; production of 200,000 eggs daily
Cycle:	infection by contaminated soil, eggs hatch in duodenum, larvae penetrate into venules/lymphatics, carried to lungs, migrate to alveoli and up the bronchial tree, swallowed, maturation in jejunum within 2.5 months
Age:	children age 1 10 years

• colic

• eosinophilia

• appendicitis

• hematemesis/pneumonitis

• jaundice (if bile ducts infested)

  Location:

  jejunum > ileum (99%), duodenum, stomach, CBD, pancreatic duct

• 15-35-cm-long tubular filling defects

• barium-filled enteric canal outlined within Ascaris

• whirled appearance, occasionally in coiled clusters ( bolus of worms )

Cx:

(1) Perforation of bowel
(2) Mechanical obstruction

Bannayan-Riley-Ruvalcaba Syndrome

• = RUVALCABA-MYHRE-SMITH SYNDROME

  Cause:

  autosomal dominant transmission

• pigmented genital lesions

• hamartomatous intestinal polyps (in 45%): usually in distal ileum + colon

• macrocephaly

• subcutaneous and visceral lipomas + hemangiomas

Barrett Esophagus

• = BARRETT SYNDROME

• = replacement of stratified squamous epithelium by metaplastic columnar epithelium (Barrett epithelium) containing goblet cells but no parietal cells

Cause:

chronic gastroesophageal reflux with epithelial injury from esophagitis

Contributing factors:

• genetic influence, reduced LES pressure, transient LES relaxation, hiatal hernia, delayed acid clearance, reduced acid sensitivity, duodenogastroesophageal reflux, alcohol, tobacco, chemotherapy, scleroderma (37%), S/P repair of esophageal atresia/esophagogastric resection/Heller esophagomyotomy

Histo:	(1) specialized columnar epithelium (proximal) (2) junctional-type epithelium (distal to above) (3) fundic-type epithelium (most distally)
Prevalence:	in general 0.3-4%; 7-10% of patients with advanced chronic reflux esophagitis
Associated with:	moderate + severe esophagitis (94%), no/mild esophagitis (6%)
Age:	0-15 years and 40-88 years (mean of 55 years); M > F; mainly among Whites

• dysphagia (due to esophageal stricture)

• signs of reflux esophagitis: heartburn, substernal chest pain, regurgitation

• low-grade upper intestinal bleeding

• asymptomatic

Location:	middle to lower esophagus
N.B.:	the squamocolumnar junction does not coincide with the GE junction, is irregular and lies > 2-3 cm orad from the gastroesophageal junction
Distribution:	circumferential/focal

P.806

• several-cm-long stricture (71%) in midesophagus (40%) or lower esophagus (60%) [DDx: peptic stricture without Barrett esophagus]

• large deep wide-mouthed peptic ulcer (= Barrett ulcer) at upwardly displaced squamocolumnar junction/within columnar epithelium

• fine reticular mucosal pattern (3-30%) resembling areae gastricae of the stomach = netlike web of barium-filled grooves surrounding small tufts of mucosa; located distally from stricture (DDx: gastroesophageal reflux, monilial + viral esophagitis, superficial spreading carcinoma)

• thickened irregular mucosal folds (28 86%)

• fine granular mucosal pattern (DDx: reflux esophagitis, acanthosis, leukoplakia, superficial spreading carcinoma, moniliasis/herpes simplex/CMV esophagitis)

• gastroesophageal reflux (45 63%)

• distal esophageal widening (34 66%; due to abnormal motility)

• hiatal hernia (75 94%)

• uptake of Tc-99m pertechnetate by columnar epithelium

Dx:	velvety pinkish red appearance of gastric-type mucosa extending from gastric mucosa into distal esophagus (endoscopy with biopsy)
Cx:	(1) Ulceration penetration into mediastinum (2) Stricture 3. Adenocarcinoma (0 10 46%;) 40-fold higher risk than general population plaquelike/focal irregularity/nodularity/sessile polyps

Rx:

(1) stop smoking, avoid bedtime snacks + foods that lower LES pressure, lose excess weight
(2) suppress gastric acidity: antacids, H₂-receptor antagonists (cimetidine, ranitidine, famotidine), H⁺K⁺-adenosintriphosphatase inhibitor (omeprazole)
(3) improve LES pressure: metoclopramide, bethanechol
(4) esophageal resection in high-grade dysplasia

Beh et Syndrome

[Hulusi Beh et (1889 1948), dermatologist in Istanbul, Turkey]

• = uncommon chronic multisystem inflammatory disorder of unknown etiology with relapsing course characterized by mucocutaneous-ocular symptoms as a triad of aphthous stomatitis, genital ulcers, ocular inflammation

  Countries:	worldwide, most common in eastern Mediterranean countries, eastern rim of Asia
  Histo:	nonspecific necrotizing vasculitis with deposition of immune complexes in walls of small blood vessels
  Age at onset:	3rd decade; M:F = 2:1
  Major criteria:	buccal + genital ulceration, ocular inflammation, skin lesions
  Minor criteria:	thrombophlebitis, GI + CNS lesions, arthritis, family history

• abdominal pain + diarrhea (50%)

@ Mucocutaneous:	aphthous stomatitis, papules, pustules, vesicles, folliculitis, erythema nodosum-like lesions
@	Genital: ulcers on penis + scrotum/vulva + vagina
@ Ocular:	relapsing iridocyclitis, hypopyon, choroiditis, papillitis, retinal vasculitis
@Articular:	mild nondestructive arthritis
@	Vascular: migratory thrombophlebitis
@CNS:	chronic meningoencephalitis
DDx:	Reiter syndrome, Stevens-Johnson syndrome, SLE, ulcerative colitis, ankylosing spondylitis

Intestinal Beh et Disease

• = large deeply penetrating intestinal ulcers (HALLMARK)

  Incidence:	10 40%
  Location:	terminal ileum, cecum, ascending colon, transverse colon

• deep round ulcers similar in appearance to peptic ulcers of stomach/duodenum

• multiple shallow/longitudinal/aphthoid ulcers

CT:

• polypoid lesion/thickened bowel wall (mural edema associated with deep ulcer penetration)

• contrast enhancement (71%)

• minimal lymphadenopathy, mostly <10 mm

Cx (56%):	panperitonitis with high mortality due to tendency for perforation at multiple sites; fistula; hemorrhage
Prognosis:	recurrence in 40 45% adjacent to surgical anastomosis
DDx:	ulcerative colitis, Crohn disease

Bezoar

[padzahr, Persian = antidote, counterpoison]

• = persistent concretions of foreign matter composed of accumulated ingested material in intestines

Incidence:	0.4% (large endoscopic series)
Etiology:	material unable to exit stomach because of large size, indigestibility, gastric outlet obstruction, poor gastric motility (diabetes, mixed connective tissue disease, myotonic dystrophy, hypothyroidism)

Predisposition:

• previous gastric surgery (vagotomy, pyloroplasty, antrectomy, partial gastrectomy), inadequate chewing, missing teeth, dentures, massive overindulgence of food with high fiber contents

• anorexia, bloating, early satiety/may be asymptomatic

Phytobezoar

• = poorly digested fibers, skin + seeds of fruits and vegetables usually forming in stomach, may become impacted in small bowel

  Incidence:

  55% of all bezoars

• history of recent ingestion of pulpy foods

Food:	oranges, persimmons (most common, unripe persimmons contain the tannin shibuol that forms a gluelike coagulum after contact with dilute acid)
Site of impaction:	stomach, jejunum, ileum

• intraluminal filling defect without constant site of attachment to bowel wall

• interstices filled with barium

• coiled-spring appearance (rare)

• partial/complete obstruction

Cx:	decubitus ulceration + pressure necrosis of bowel wall, perforation, peritonitis
DDx:	lobulated/villous adenoma, leiomyosarcoma, metastatic melanoma, intussusception

P.807

Trichobezoar

[trikho-, thrix, Greek = hair]

• 80% are < age 30, almost exclusively in females;

Associated with:

gastric ulcer in 24 70%

Blue Rubber Bleb Nevus Syndrome

• = rare disorder characterized by vascular hamartomas of skin + visceral hemangiomas predominantly afflicting the GI tract (but also liver, spleen, heart, skeletal muscle, lung, kidney, thyroid, eyes, CNS)

  Etiology:	sporadic/autosomal dominant
  Path:	thin layer of connective tissue + single layer of endothelial cells surrounding blood-filled ectatic vessels

• red to deep blue soft painless cutaneous lesions evacuating under pressure + slow refilling (commonly present at birth increase in size and number with age)

• iron deficiency anemia (due to spontaneous hemorrhage)

• nodular filling defects throughout small bowel

MR:

• hyperintense lesions on T2WI (due to slow flow/thrombosis)

Cx:

intussusception, volvulus; pressure erosion of bone, osseous + soft-tissue hypertrophy (secondary to hypervascularity)

DDx:

• Maffucci syndrome (dyschondroplasia + osteochondromas + vascular malformations)

• Klippel-Trenaunay-Weber syndrome (port wine stain, vascular malformations, limb hypertrophy)

• Kasabach-Merritt syndrome (large vascular malformations + consumptive coagulopathy)

• Kaposi sarcoma

• Peutz-Jeghers syndrome (congenital polyposis + melanotic cutaneous lesions)

• Gardner syndrome (soft-tissue tumors + sebaceous cysts)

Blunt Abdominal Trauma

• CT is imaging method of choice for evaluation of stable patients

• US imaging in the detection of intraabdominal injury:

  • 86% sensitive, 99% specific, 98% accurate

Hemoperitoneum

Frequency:	29 34% of patients with abdominal visceral injury have no hemoperitoneum
Location:	paracolic gutters, pelvis

CT (negative predictive value of 99.6%):

Attenuation values of blood:

• during IV contrast administration and assuming an initially normal hematocrit without significant dilution from intraperitoneal fluid (ascites, urine, succus, lavage fluid)

  serum (after hematocrit effect)	0 20 HU
  fresh unclotted blood	30 45 HU
  	clotted blood 60 100 HU
  active arterial extravasation	>180 HU

• sentinel clot sign = the highest attenuation value of blood clot marks the anatomic site of visceral injury

• high-density active arterial extravasation always surrounded by lower-density hematoma (DDx: extravasated oral contrast is not surrounded by lower-density material)

US:

• usually anechoic fluid accumulation in subhepatic space (= Morison pouch) > pouch of Douglas/paravesical space > between bowel loops

  DDx:

  bowel contents, urine, bile, ascites

• hemoperitoneum score = depth of largest fluid collection in cm + 1 point for each additional site with fluid (score of 2 managed conservatively)

• hyperechoic/occasionally isoechoic masses (= intraperitoneal clot)

Prognosis:

17% of patients without hemoperitoneum require surgical/angiographic intervention

• Peritoneal lavage cannot quantify amount of hemoperitoneum + results in a 19 39% rate of nontherapeutic surgeries

Hypovolemia = Hypoperfusion complex

• collapsed cava sign = persistent flattening of IVC (due to decreased venous return)

  N.B.:

  abort CT examination as shock is imminent!

• small hypodense spleen (decreased enhancement)

• small aorta + mesenteric arteries (due to intense vasoconstriction)

• shock nephrogram = lack of renal contrast excretion

• shock bowel = dilatation of fluid-filled intestines + generalized thickening of small bowel folds + increased enhancement (due to vasoconstriction of mesenteric vessels)

• marked enhancement of adrenal gland

• intense pancreatic enhancement

Categories of Splenic Injury
Grade	Injury	Description
I	hematoma	subcapsular <25% of surface area
	laceration	capsular tear <1 cm of parenchymal depth
II	hematoma	subcapsular 25-50% of surface area; intraparenchymal <5 cm in diameter
	laceration	1-3 cm deep without involvement of trabecular vessel
III	hematoma	subcapsular >50% of surface area; ruptured subcapsular/parenchymal; intraparenchymal >10 cm/expanding
	laceration	>3 cm parenchymal depth/involvement of trabecular vessels
IV	laceration	involving segmental/hilar vessels with devascularization of >25%
V	laceration	completely shattered spleen
	vascular	total splenic devascularization

Blunt Trauma To Spleen

• Most frequently injured intraperitoneal organ in blunt abdominal trauma

Associated with:

other solid visceral/bowel injuries (29%); lower rib fractures in 44%, injury to left kidney in 10%, injury to left diaphragm in 2%

P.808

• 20% of left rib fractures have splenic injury!

• 25% of left renal injury have splenic injury!

Technique:

scanning delay of 60 70 seconds to avoid heterogeneous splenic enhancement

CECT (95% accurate):

• CT not reliable to determine need for surgical intervention!

• hemoperitoneum (indicates disruption of splenic capsule)

• sentinel clot (= area of >60 HU adjacent to spleen) sensitive predictor of splenic injury =perisplenic hematoma

• high-attenuation area (80 370 HU) =active extravasation/pseudoaneurysm:

  N.B.:

  active extravasation of contrast material usually requires surgery

• mottled parenchymal enhancement =contusion

• hypoattenuating line connecting opposing visceral surfaces = linear parenchymal defect =splenic laceration:

  • almost always associated with hemoperitoneum

• crescentic region of low attenuation along splenic margin flattening/indenting/compressing the normal parenchyma =subcapsular hematoma

• round hypodense inhomogeneous region hyperdense clot =intrasplenic hematoma

• hypoattenuating hematoma with complete separation of splenic fragments = laceration traversing two capsular surfaces =splenic fracture

• multiple lacerations = shattered spleen

US:

• hyperechoic intraparenchymal region (= acute hematoma/laceration)

• anechoic intralesional collection (= brisk hemorrhage)

• diffusely heterogeneous parenchymal pattern containing hyper- and hypo-echoic areas (= extensive splenic injury)

• loss of normal organ contour (= perisplenic clot)

Sequelae:

• scar/fibrosis

• splenic pseudocyst (20 30 HU)

• pseudoaneurysm formation

• delayed splenic rupture

  • = hemorrhage >48 hours after trauma

  Cause:	subcapsular hematoma
  Prevalence:	0.3 20% of blunt splenic injuries
  Time of onset:	in 70% within 2 weeks of injury, in 90% within 4 weeks of injury
  Prognosis:	52% surgery (splenectomy [8%], splenorrhaphy), 48% nonsurgical management
  Rx:	up to 91% of stable patients can be treated conservatively with observation; transcatheter embolization
  DDx:	(1) Normal lobulation/splenic cleft (smoothly contoured, medially located) (2) Adjacent unopacified jejunum simulating splenic tissue (3) Early differential enhancement of red and white pulp (scan obtained within 20 50 seconds) (4) Perisplenic fluid from ascites/urine/succus/bile/lavage

Distribution of Traumatic Hepatic Lesions

Blunt Trauma To Liver (20%)

• Second most frequently injured intraabdominal viscus

  Associated with:

  splenic injury in 45%

• clinical manifestation often delayed by days/weeks

Location:	R > L lobe
Site:	perivascular, paralleling right + middle hepatic arteries + posterior branches of right portal vein, avulsion of right hepatic vein from IVC (13%) Left lobe injury more often associated with damage to duodenum, pancreas, transverse colon

Categories of Splenic Injury
Grade	Injury	Description
I	hematoma	subcapsular <10% of surface area
	laceration	capsular tear <1 cm of parenchymal depth
II	hematoma	subcapsular 10-50% of surface area; intraparenchymal <10 cm in diameter
	laceration	1-3 cm deep and <10 cm long
III	hematoma	subcapsular >50% of surface area; ruptured subcapsular/parenchymal; intraparenchymal >10 cm/expanding
	laceration	>3 cm parenchymal depth
IV	laceration	parenchymal disruption 25-75% of lobe; 1-3 Couinaud segments in single lobe
V	laceration	disruption >75% of single lobe; >3 Couinaud segments in single lobe
	vascular	juxtahepatic venous injury (HV, IVC)
VI	vascular	hepatic avulsion

CECT:

• hypoattenuating hematoma:

  • lenticular configuration (= subcapsular hematoma) usually resolving within 6-8 weeks

  • irregular linear branching/round regions of low attenuation = laceration

  • focal/diffuse periportal tracking (in up to 22%) due to dissecting hemorrhage/bile/dilated periportal lymphatics (secondary to elevated central venous pressure/injury to lymphatics)

  P.809

  
  

  • alteration in distribution of vessels + ducts

• hypodense wedge extending to liver surface = focal hepatic devascularization

• focal hyperdense (80-350 HU) area = active hemorrhage/pseudoaneurysm

• hemoperitoneum (inability of liver veins to contract)

• intrahepatic/subcapsular gas (usually due to necrosis)

US:

• localized area of increased intraparenchymal echogenicity (= acute hematoma/laceration)

• widespread heterogeneous liver echogenicity + absence of normal vascular pattern (= global parenchymal injury)

Cx:	in up to 20% (1) delayed rupture (rare) (2) hemobilia (3) arteriovenous fistula/pseudoaneurysm (4) biloma infection (5) superinfection of hematoma/devascularized hepatic parenchyma
Rx:	conservative treatment in up to 80% in adults + 97% in children; transcatheter embolization
Healing:	1-6-15 months
DDx:	(1) beam-hardening artifact from adjacent ribs/from air-contrast level in stomach (2) Focal fatty infiltration

Blunt Trauma to Gallbladder (2%)

Associated with:

injury to liver, duodenum

• pericholecystic fluid (extraperitoneal location of GB)

• free intraperitoneal fluid

CECT:

• blurred contour of GB

• focal thickening/discontinuity of GB wall

• intraluminal enhancing mucosal flap

• hyperattenuating blood within GB lumen

• mass effect on adjacent duodenum

• collapsed GB = GB rupture

• focal periportal tracking = GB rupture

US:

• focal hypoechoic thickening

• echogenic mass within GB lumen

Blunt Trauma to GI Tract (5%)

Cause in children:	MVA (lap belts), bicycle handle bar, child abuse
May be associated with:	Chance fracture; traumatic hernia (disruption of the rectus abdominis muscle)
Location:	jejunum distal to ligament of Treitz > duodenum > ascending colon at ileocecal valve > descending colon

• abdominal tenderness (100% sensitive)

• increased temperature + heart rate

• decreased urine output over 24 hours

• lap belt ecchymosis

NECT:

• pneumoperitoneum (15 32%):

• small gas bubbles anteriorly near liver/trapped within leaves of mesentery (with small bowel perforation)

• retroperitoneal air (with disruption of duodenum/colon)

• hypodense free fluid (58 85%), particularly in interloop location due to perforation

  DDx:

  parenchymal organ injury/osseous injury/large vessel injury/bladder perforation

• sentinel clot sign adjacent to bowel

CECT (88 92% sensitive):

• focal discontinuity of bowel wall = direct evidence

• focal bowel wall thickening > 3 mm (= intramural hematoma (75%)/vascular compromise and inflammation due to spilling of bowel contents):

  • intestinal obstruction

• hyperdense contrast enhancement of injured bowel wall = delayed venous transit time (20%)

• stranding of mesentery = streaky hyperattenuating infiltration/fluid at mesenteric root (due to hemorrhage + inflammatory response)

• mesenteric hematoma (39%)

• extravasation of oral contrast material (uncommon), most dense near perforation

  DDx:

  hyperattenuating blood, extravasating vascular contrast material, leak of contrast material from urinary tract

• mesenteric pseudoaneurysm

US:

• nonspecific free fluid (98% sensitive)

N.B.:

clinical signs + symptoms may be delayed for 24 hours (increasing mortality to 65%)

Blunt Trauma to Pancreas (3%)

Mechanism:	compression against vertebral column with shear across pancreatic neck
Incidence:	<10% of childhood trauma
Cause:	motor vehicle accident, fall onto handle bars of a bicycle, child abuse
Associated with:	injury to liver, duodenum

Classification:

I	minor contusion/hematoma, capsule + major duct intact
II	parenchymal injury without major duct injury
III	major ductal injury
IV	severe crush injury
Location:	junction of body + tail

• posttraumatic pancreatitis:

  • edema/fluid in peripancreatic fat

  • focal/diffuse pancreatic enlargement

  • irregularity of pancreatic contour

• area of low-attenuation = contusion/laceration (actual site of laceration difficult to visualize)

• fluid around superior mesenteric artery

• fluid in transverse mesocolon/lesser sac

• fluid between pancreas and splenic vein

• thickening of anterior pararenal fascia

N.B.:	24 48-hour delayed scans uncover findings not present earlier
Rx:	I + II conservative management; III + IV need surgery within 24 hours
Cx:	recurrent pancreatitis, pseudocyst, pseudoaneurysm, fistula, abscess (attendant mortality of 20%)

P.810

Boerhaave Syndrome

• = complete transmural disruption of esophageal wall with extrusion of gastric content into mediastinum/pleural space secondary to food bolus impaction

• forceful vomiting with sudden onset of pain (substernal, left chest, in neck, pleuritic, abdominal)

• dyspnea

• NO hematemesis (blood escapes outside esophageal lumen)

• rent of 2 5 cm in length, 2 3 cm above GE junction, predominantly on left posterolateral wall

• pleural effusion on left >> right side/hydropneumothorax

• pneumomediastinum (single most important plain-film finding), pneumopericardium, subcutaneous air

• V sign of Naclerio = localized mediastinal emphysema with air between lower thoracic aorta + diaphragm

• mediastinal widening

• air-fluid level within mediastinum

• extravasation of contrast medium into mediastinum/pleura

Brunner Gland Hyperplasia

• = BRUNNER GLAND HAMARTOMA

Incidence:	1.2% of all gastric polyps
Etiology:	response to increased acid secretion
Histo:	diffusely enlarged hyperplastic glands with Swiss cheese appearance
Physiology:	secrete a clear viscous alkaline mucus into crypts of Lieberk hn

MORPHOLOGIC TYPES:

• Diffuse nodular hyperplasia

• Circumscribed nodular hyperplasia: in suprapapillary portion

• Single adenomatous hyperplastic polyp: in duodenal bulb

Location:

duodenum, prepyloric region (duodenal glands begin in vicinity of pylorus extending distally within proximal 2/3 of duodenum)

• multiple nodular filling defects (usually limited to 1st portion of duodenum) with cobblestone appearance (most common finding)

  DDx:

  polyposis syndromes, lymphoid hyperplasia, heterotopic gastric mucosa, nodular duodenitis

• occasionally single mass up to 5 cm central ulceration

  DDx:	adenomatous polyp, various submucosal tumors
  Cx:	GI bleeding, obstruction, intussusception

Burkitt Lymphoma

• = most common type of pediatric non-Hodgkin lymphoma; initially described in a 7-year old Ugandan child in 1958 by Dennis Burkitt, a British surgeon

  Etiology:	tumor from undifferentiated small noncleaved B-cell derived lymphocytes
  Path:	resemblance to Hodgkin disease
  Histo:	characteristic starry sky pattern

• fastest growing tumor in humans with a potential doubling time of 24 hours

• paraplegia

• NO peripheral leukemia

• conspicuous absence of lymph node disease

• tendency to permeate/destroy bone

MR:

• isointense to muscle on T1WI + T2WI

• intense homogeneous enhancement

Rx:	dramatic response to chemotherapy
Prognosis:	long-term survival in 50%

Endemic Form of Burkitt Lymphoma

Endemic in areas with malaria:

• sub-Saharan Africa, New Guinea (exposure to Plasmodium falciparum has a synergistic effect causing a marked decrease in T-cell surveillance)

Incidence in central Africa:

• 50 80% of all childhood neoplasms

Associated with:	Epstein-Barr virus infection in 95% (implicated as a B-cell mitogen in the oncogenesis)
Age:	3 10 years

• @ Mandible (first)/maxilla/facial bones

  • jaw mass

  • exophthalmos (orbital extension)

  • grossly destructive lesion, spicules of bone growing at right angles

  • large soft-tissue mass

• @ Other skeleton (multifocal in 10%)

  • reminiscent of Ewing tumor/reticulum cell sarcoma

  • lamellated periosteal reaction around major long bones

Sporadic Form of Burkitt Lymphoma

• = NONENDEMIC FORM OF BURKITT LYMPHOMA

Incidence in Europe + North America:

• 35 45% of all pediatric NHL; 3% of all childhood tumors

Age:

6 15 years

• Epstein-Barr virus genome found in only a minority

• @ Abdomen (69%)

  • tumors of small bowel (Peyer patches of terminal ileum), mesentery

  • abdominal mass

  • intestinal obstruction

  • usually intraabdominal extranodal involvement with sparing of spleen

  • well-defined sharply marginated homogeneous tumors (75%)

  • ascites (13%)

• @ Genitourinary tract (20%)

  • ovary, uterus, kidneys, retroperitoneum

  • renal masses/diffuse enlargement (5%)

  • hydronephrosis (28%)

• @ Chest

  • pleural effusion (most common chest abnormality)

• @ CNS

  • meningeal infiltration (most commonly)

  • cavernous sinus invasion

  • supra- and parasellar tumor

  • epidural spinal mass spinal cord compression

• @ Others

  • salivary glands, thyroid, bone marrow

P.811

Carcinoid

• = most common primary tumor of small bowel + appendix (>95% of all carcinoids); belongs to APUDomas (like pheochromocytoma, medullary carcinoma of thyroid, islet cell tumors of pancreas)

Age:	5th 6th decade; M:F = 2:1
Path:	firm yellow submucosal nodule arising from argentophil Kulchitsky cells in the crypts of Lieberk hn (= argentaffinoma due to affinity for silver stain); invasion into mesentery incites an intense fibrotic reaction
Histo:	low-grade malignancy = resemble adeno-carcinomas but do not have their aggressive behavior; malignant through invasion of muscularis

Biochemistry:

• tumor elaborates (1) ACTH, (2) histamine, (3) bradykinin (4) kallikrein, (5) prostaglandin, (6) serotonin = 5-hydroxytryptamine (from tryptophan over 5-hydroxytryptophan), which is metabolized in liver by monamine oxidase into 5-hydroxyindole acetic acid (5-HIAA) and excreted in urine; 5-hydroxytryptophan is destroyed in pulmonary circulation

Associated with:

other synchronous/metachronous malignancies (36% at necropsy); neurofibromatosis type 1

• asymptomatic (66%)

• abdominal pain/obstruction (19%)

• nausea, weight loss (16%)

• palpable mass (14%)

• GI bleeding

• Carcinoid syndrome (in 7% of small bowel carcinoids):

  • = constellation of clinical findings related to hormone secretion by tumor

  Cause:

  excess serotonin levels when the metabolic pathway to 5-HIAA (in liver) is bypassed
  (a) with liver metastases
  (b) with primary pulmonary/ovarian carcinoids

• recurrent diarrhea (70%)

• right-sided endocardial fibroelastosis (35%) resulting in tricuspid regurgitation + pulmonary valve stenosis + right heart failure

• attacks precipitated by ingestion of food/alcohol

• asthmatic wheezing from bronchospasm (15%)

• desquamative skin lesions (5%)

• pellagra (7%) from niacin deficiency as a result of preferential conversion of dietary tryptophan to serotonin rather than niacin

• multiple telangiectasias (25%)

• nausea & vomiting, fever

• hypotension (vasomotor instability)

• cutaneous facial flushing (rare)

• excess 5-HIAA in urine

Prognosis:	carcinoid syndrome has a higher morbidity & mortality than does the tumor itself!
RULE OF 1/3:	1/3 occur in small bowel 1/3 have metastases 1/3 are multiple 1/3 have a second malignancy

Metastases:

• to mesenteric lymph nodes, liver (in 90% of patients with carcinoid syndrome), lung, bone (osteoblastic), peritoneum

• incidence versus tumor size

  tumor of	<1 cm	(in 75%)	metastasizes in	2%
  tumor of	1 2 cm	(in 20%)	metastasizes in	50%
  tumor of	>2 cm	(in 5%)	metastasizes in	85%

• incidence versus location

  tumor in ileum	(in 28%)	metastasizes in	35%
  tumor in appendix	(in 46%)	metastasizes in	3%
  tumor in rectum	(in 17%)	metastasizes in	1%

Liver metastases seen:	best/	(only) on:
(a) NECT	35%	(3%)
(b) CECT in HAP	35%	(14%)
(c) CECT in PVP	30%	(3%)

HAP = hepatic arterial-dominant phase of triple phase CT

PVP = portal venous-dominant phase of triple phase CT

Location:

between gastric cardia and anus (85% in GI tract; 15% in lungs + bronchi)

• @ Appendix (30 45%)

  Commonly benign:	slow growth, rarely metastasizing
  Incidence at surgery:	0.03 0.7%
  Site:	tip (70%), middle (20%), base (10%) of appendix

  • symptoms of appendicitis

  • invasion of mesoappendix (11%)

• @ Small bowel (25 35%)

  Incidence:	25% of all small bowel tumors
  Location:	ileum (91%); jejunum (7%), duodenum (2%); multiple in 15 29 41%

  • 75% of patients with symptomatic spread have midgut carcinoids

  • 30% have a second primary malignancy of GI tract

  • Duodenal carcinoids are associated with multiple endocrine neoplasia

  • Periampullary carcinoids are associated with neurofibromatosis type 1 + often contain somatostatin-producing cells

• @ Rectum (10 15%): metastasize in 10%

• @ Colon (5%): ascending colon, often malignant

• @ Stomach (<3%): lesser curvature of distal antrum

  • one/more 1 4-cm submucosal masses:

    • bull's eye appearance when ulcerated

  • one/more sessile/pedunculated polyps

• @ Other organs (5%): bronchus, thyroid, pancreas, biliary tract, teratomas (ovarian, sacrococcygeal, testicular)

• @ may be multicentric

UGI:

• small smooth submucosal mass (usually <2 cm) impinging eccentrically on lumen

• desmoplastic response of mesentery from locally high levels of serotonin causes:

  • angulation + kinking of loops leading to obstruction (DIAGNOSTIC)

  • spiculated/tethered appearance of mucosal folds

  • matting of multiple loops

• separation of loops due to large mesenteric metastases

CT:

• submucosal vascular lesion (dual-phase imaging with water as oral contrast)

• focal calcified mesenteric mass surrounded by thickened mesentery:

  • stellate radiating pattern + beading of mesenteric neurovascular bundles (desmoplastic reaction)

  • retraction + shortening of mesentery

  P.812

  
  

  • displacement + kinking + separation of adjacent bowel loops

  • segmental thickening of adjacent bowel loops (encasement of mesenteric vessels leads to chronic ischemia)

• low-density lymphadenopathy (due to necrosis)

• characteristically hyperattenuating liver metastases in early arterial phase

• may become isodense after slow contrast infusion/in portal-venous phase

Angio:

• sunburst appearance:

  • kinking of small- and medium-sized vessels with a stellate configuration

  • simulated hypervascularity with thickening + foreshortening of mesenteric vessels secondary to fibrotic retraction

• mesenteric ischemia:

  • arterial branch stenoses from encasement of mediumsized vessels (due to elastic vascular sclerosis with locally elevated serotonin levels)

  • venous occlusion/mesenteric varices

• tumor may be identified as hypervascular mass

NUC (I-123 MIBG imaging):

• uptake in 44-63% (higher frequency of radiotracer uptake in midgut carcinoids + with elevated serotonin levels)

US:

• persistent fluid-distended appendix without typical signs of appendicitis

Prognosis:	slow progression with average survival time of 3.2 years after diagnosis of liver metastases; 5-year survival of 65% for localized disease + 36% for distant metastatic disease
Rx:	resection; somatostatin/SMS 201-995; chemoembolization of hepatic arteries
DDx:	oat-cell carcinoma, pancreatic carcinoma, medullary thyroid carcinoma, retractile mesenteritis, desmoplastic carcinoma/lymphoma

Cathartic Colon

• = prolonged use of stimulant-irritant cathartics (>15 years) resulting in neuromuscular incoordination from chronically increased muscular activity + tonus

  Agents:	castor oil, senna, phenolphthalein, cascara, podophyllum, aloin
  Location:	involvement of colon proximal to splenic flexure

• effaced mucosa with flattened smooth surface

• diminished/absent haustrations

• pseudostrictures = smoothly tapered areas of narrowing are typical (sustained tonus of circular muscles)

• poor evacuation of barium

• flattened + gaping ileocecal valve

• shortened but distensible ascending colon

DDx:

burned-out ulcerative colitis with right-sided predominance (very similar)

Chagas Disease

[Carlos Chagas (1879-1934), physician in Rio de Janeiro, Brazil]

• = damage of ganglion cells by neurotoxin liberated from protozoa Trypanosoma cruzi resulting in aperistalsis of GI tract + dilatation

Endemic to Central + South America (esp. eastern Brazil)

Histo:	decreased number of cells in medullary dorsal motor nucleus + Wallerian degeneration of vagus + decrease/loss of argyrophilic cells in myenteric plexus of Auerbach
Peak age:	30 50 years; M:F = 1:1

• intermittent/persistent dysphagia

• odynophagia (= fear of swallowing)

• foul breath, regurgitation, aspiration

• Mecholyl test: abnormal response indicative of deficient innervation; 2.5 10 mg methacholine subcutaneously followed by severe tetanic nonperistaltic contraction 2 5 minutes after injection, commonly in distal half of esophagus, accompanied by severe pain

• @ Dilatative cardiomyopathy (myocarditis)

• @ Megacolon (bowels move at intervals of 8 days to 5 months)

  Cx:

  impacted feces, sigmoid volvulus

• @ Esophagus: changes as in achalasia

Chalasia

• = continuously relaxed sphincter with free reflux in the absence of a sliding hernia

  Etiology:

  elevated submerged segment

Causes:

• Delayed development of esophagogastric region in newborns

• Scleroderma, Raynaud disease

• S/P forceful dilatation/myotomy for achalasia

• free/easily induced reflux

Colitis Cystica Profunda

• = rare benign condition characterized by submucosal mucus-containing cysts lined by normal colonic epithelium

  Etiology:	probably related to chronic inflammation
  Associated with:	solitary rectal ulcer syndrome (in localized form)
  Age:	primarily disease of young adults

• brief periods of bright red rectal bleeding

• mucous/bloody discharge

• intermittent diarrhea

Location:

• (a) localized to rectum (most commonly)/sigmoid

• (b) generalized colonic process (less common)

• nodular polypoid/cauliflower-like lesions <2 cm in size, containing no gas

• spiculations mimicking ulcers (barium-filled clefts between nodules)

DDx:

pneumatosis (rarely affects rectum)

Colonic Atresia

Incidence:

less common than ileal atresia

Plain radiograph:

• massive dilatation of colon proximal to obstruction

• mottled pattern of gas + feces proximal to point of atresia

DDx:

often indistinguishable from obstruction of distal ileum

BE:

• functional microcolon

• obstruction to retrograde flow of barium

P.813

US:

• dilated hyperechoic distal small bowel + proximal colon (from retained meconium)

Colorectal Carcinoma

• Most common cancer of GI tract; 3rd most commonly diagnosed malignancy in developed countries in men (after lung + prostate cancer) and women (after lung + breast cancer); 2nd leading cause of cancer deaths

Incidence:	11% of all newly diagnosed cancers; 13% of all cancer deaths; 150,000 new cases/year with 57,000 deaths in United States (1999); 6% lifetime probability of any White person to develop colorectal cancer; 3:100,000 in 30 34-year-olds; 532:100,000 for >85-year-olds
Lifetime probability:	4%

Risk factors:

• Personal history of colonic adenoma/carcinoma

  • malignancy in 5% of tubular adenomas

  • malignancy in 30 40% of villous adenomas

  Proof of adenoma-carcinoma sequence:

  • frequent coexistence of adenoma + carcinoma

  • similar distribution within colon

  • consistent proportional prevalence in population having varied magnitudes of colon cancer risk

  • increased frequency of carcinoma in patients with adenomas

  • reduction of cancer incidence following endoscopic removal of polyps

  • all patients with familial adenomatous polyposis syndrome develop colon carcinoma if colon not removed

  • similarity of DNA + chromosomal constitution

  • 93% of colorectal carcinomas arise from adenomatous polyp!

  • A patient with one adenoma has a 9% chance of having a colorectal carcinoma in next 15 years!

  • It takes about 7 years for a 1-cm adenoma to become an invasive cancer!

  • 5% of adenomas 5 mm in size develop into invasive cancers (5 mm is considered critical mass of intraepithelial neoplasia)!

• Family history of benign/malignant colorectal tumors in first-degree relatives (3 5 risk)

• Personal history of ovarian/endometrial/breast cancer

• Dysplasia of colon within flat mucosa

• Inflammatory bowel disease:

  • Ulcerative colitis (3 5% incidence; cumulative incidence of 26% after 25 years of colitic symptoms)

  • Crohn disease affecting the colon + rectum (particularly in bypassed loops/in vicinity of chronic fistula)

  Time delay:	>8 10 years of colitis
  Underlying lesion:	dysplasia within flat mucosa

• Prominent lymphoid follicular pattern

• Pelvic irradiation

• Ureterosigmoidostomy

Environmental risk factors:

• low fiber diet: prevents rapid transit time thus increasing contact time between potential toxins and colonic mucosa

• increased ingestion of fat + animal protein

• obesity

• asbestos worker

Genetic risk factors (6% of colorectal carcinomas):

• familial adenomatous polyposis syndrome: familial polyposis, Gardner syndrome, Turcot syndrome

  Age:

  approximately at 40 years

• certain hamartomatous polyposis syndromes:Peutz-Jeghers syndrome, juvenile polyposis, Cowden disease

• hereditary nonpolyposis colon cancer syndrome

  • = Lynch syndrome (see below)

Screening recommendations (American Cancer Society):

• as/more effective than mammographic screening

• (a) for persons >50 years of age: annual fecal occult-blood test + sigmoidoscopy/BE every 3 5 years

• (b) for first-degree relatives of patients with colon cancer screening should start at age 40

Age:

median age of 71 years for colon cancer; median age of 69 years for rectal cancer; M:F = 3:2

Histo:

• Adenocarcinoma with varied degrees of differentiation

• Mucinous carcinoma (uncommon)

• Squamous cell carcinoma + adenoacanthoma (rare)

Metastases (lymphatic/hematogenous venous):

• Liver (75%; 15 20% at time of surgery) due to portal venous drainage route

• Mesentery + mesenteric nodes (10 15%)

• Adrenal (10 14%)

• Lung (5 50%)

• Ovary (3 8%) = Krukenberg tumor

• Psoas muscle tumor deposit

• Peritoneal metastases:

  • malignant ascites: usually associated with poorly differentiated colonic carcinoma

  • pseudomyxoma peritonei (<5%): low-grade colonic adenocarcinoma

• Bone (5%)

• Brain (5%)

  • Because of absence of lymphatics in lamina propria colon cancer will not metastasize until it penetrates the muscularis mucosa!

• rectal bleeding, iron deficiency anemia

• change in bowel habits/caliber of stools

• obstruction (poor prognostic indicator)

• hydronephrosis (13%)

• positive fecal occult blood testing (2 6% positive-result rate; 5 10% positive predictive value; fails to detect 30 50% of colorectal carcinomas + up to 75% of adenomas):

  • Hemoccult (hematein), HemoQuant (porphyrins), Haemselect (hemoglobin)

• progressive elevation of carcinoembryonic antigen (CEA) >10 g/L indicative of recurrent/metastatic disease

• watery diarrhea + potassium depletion/excessive secretion of mucus + hypoalbuminemia (in large mucin-secreting villous tumor)

Location:

aging gut = number of right-sided lesions increasing with age ( changing distribution )

P.814

• left colon (52 61%):

  • rectum (15 33 41%), sigmoid (20 37%), descending colon (10 11%)

  • commonly annular strictures with obstruction

• right colon:

  • transverse colon (12%), ascending colon (8 16%), cecum (8 10%)

    • commonly polypoid lesions with chronic bleeding + intussusception

Colonoscopy:	cecum not visualized in 10 36%; fails to detect 12% of colonic polyps (10% in areas never reached by colonoscope)
Cx:	perforation in 0.2% (0.02% for BE); death in 1:5,000 (1:50,000 for BE)

BE (sensitivities in detection of polyps >1 cm: SCBE 77 94%, DCBE 82 97%; for polyps <1 cm: SCBE 18 72%, DCBE 61 83%):

• fungating polypoid carcinoma:

  • chronic bleeding, intussusception

• annular ulcerating carcinoma = apple core lesion

  • = annular constriction is a result of tumor growing along the lymphatic channels, which parallel the circular muscle fibers of the inner layer of the muscularis propria; longitudinal growth is limited with abrupt transition to normal mucosa

  • colonic obstruction

• saddle lesion = growth characteristics between polypoid mass + annular constricting lesion

• scirrhous carcinoma (signet-ring type)

  • = long-segment stricture without significant mucosal abnormality similar to linitis plastica due to diffuse circumferential + longitudinal tumor infiltration within the loose submucosal tissue between muscularis mucosa + muscularis propria

  • often seen in ulcerative colitis

• curvilinear/mottled calcifications (rare) are CHARACTERISTIC of mucinous adenocarcinoma

CT (48 90% staging accuracy, 25 73% for lymph node metastases):

• CT staging (poor accuracy compared with Astler-Coller classification):

  Stage 1	intramural polypoid mass
  Stage 2	thickening of bowel wall
  Stage 3	slight invasion of surrounding tissues
  Stage 4	massive invasion of surrounding tissue + adjacent organs/distant metastases

  Staging of colorectal cancer (modified Dukes = Astler-Coller classification):
  Stage	Findings
  A	limited to mucosa
  B	involvement of muscularis propria
  B1	extension into muscularis propria
  B2	extension through muscularis propria into serosa/mesenteric fat (35%)
  C	lymph node metastases (50%)
  C1	+ growth limited to bowel wall
  C2	+ growth extending into adipose tissue
  D	distant metastases

  Staging of Colorectal Cancer (UICC-AJCC Colorectal Cancer Staging System)
  Stage		Grouping		5-year Survival
  0	Tis	N0	M0	>95%
  I	T1	N0	M0	75-100%
  	T2	N0	M0
  II	T3	N0	M0	50-75%
  	T4	N0	M0
  III	any T	N1	M0	30-50%
  	any T	N2,3	M0
  IV	any T	any N	M1	<10%
  Legend:
  Tis	carcinoma in situ
  T1	invasion of submucosa
  T2	invasion of muscularis propria
  T3	invasion of subserosa/pericolic tissue
  T4	invasion of visceral peritoneum/other organs
  N1	1 3 pericolic Lnn
  N2	>4 pericolic Lnn
  N3	any Lnn along course of a vascular trunk

• low-density mass + low-density lymph nodes in mucinous adenocarcinoma (= >50% of tumor composed of extracellular mucin)

• psammomatous calcifications in mucinous adenocarcinoma

• signs of Lnn involvement: single lymph node >1 cm in diameter/cluster of 3 nodes <1 cm/node of any size within mesentery

MR (staging accuracy of 73%, 40% sensitivity for lymph node metastases)

Prognosis:

• Survival rate of 40 50% overall in 5 years (unchanged over past 40 years); 80 90% with Duke A; 70% with Duke B; 33% with Duke C; 5% with Duke D

• Recurrence in 1/3 of patients:

  • local recurrence at line of anastomosis (60%) within 1 year after resection in 50%, within 2 years after resection in 70 80%

  • distant metastases (26%)

  • local recurrence + metastases (14%)

• Risk after detection of colon cancer:

  5%	for synchronous colon cancer
  14%	for synchronous cancer with sentinel polyp
  35%	for additional adenomatous polyp
  3%	for metachronous colon cancer
  4%	for extracolonic malignancy

Cx:

(1) Obstruction (frequently in descending + sigmoid colon)
(2) Perforation
(3) Intussusception
(4) Abscess formation
(5) Fistula formation
(6) Pneumatosis cystoides intestinalis
(7) Pseudomyxoma peritonei (from low-grade adenocarcinoma of colon)

Rx:	(1) Local surgical excision/polypectomy for stage I disease (2) Right/left hemicolectomy with eventual anastomosis of proximal + distal excision sites (3) Low anterior resection: >2 cm of rectum must remain to anastomose the colon (4) Abdominoperineal resection with colostomy for low rectal carcinoma (5) Adjuvant chemotherapy for stage II disease (fluorouracil/levamisole)
DDx:	(1) Prolapsing ileocecal valve (change on palpation) (2) Spasm (intact mucosa, released by propantheline bromide) (3) Diverticulitis

P.815

Lynch Syndrome

• = HEREDITARY NONPOLYPOSIS COLORECTAL CANCER SYNDROME

• = families with high incidence of colorectal cancers + increased incidence of synchronous and metachronous colorectal cancers

Amsterdam criteria:

• 3 family members of whom 2 are 1st degree relatives of the third

• family members in 2 generations

• one family member diagnosed <50 years of age

Lynch I	= no associated extracolonic cancer
Lynch II	= associated with extracolonic malignancy: transitional cell carcinoma of ureter + renal pelvis; adenocarcinoma of endometrium, stomach, small bowel, pancreas, biliary tract, brain; hematologic malignancy; carcinoma of skin + larynx
Etiology:	autosomal dominant abnormality of chromosome 2 with defect in DNA replication-repair process (a) accelerated adenoma-carcinoma sequence (b) dysplasia in flat mucosa of colon
Prevalence:	5-10% of patients with colon cancer; 5 more common than familial adenomatous polyposis syndrome
Mean age:	45 years
Location:	70% proximal to splenic flexure
Prognosis:	better stage for stage than in other cancers (5-year survival rate of 65% versus 44% in sporadic cases)
Surveillance:	colonoscopy every 1-2 years from ages 22-35 years

Pathologic staging of rectal cancer
Astler-Coller/TNM		Description	5-year Survival
A	T1,N0,M0	limited to submucosa	80%
B1	T2,N0,M0	limited to muscularis propria	70%
B2	T3,N0,M0	transmural extension	60-65%
C1	T2,N1,M0	nodes (+), into muscularis	35-45%
C2	T3,N1,M0	nodes (+), transmural	25%
	T4	invasion of adjacent organs
D	M1	distant metastasis	<25%

Rectal Cancer

Incidence:

45,000 rectal cancers/year in United States

Hematogenous metastasis:

• dual venous drainage into portal + systemic veins

  • may have lung without liver metastases

Risk of recurrence:

5%	for T1
10%	for T2	33% for T1, N1 + T2N1
25%	for T3	66% for T3N1
50%	for T4

Staging accuracy:

• Digital rectal examination: 68-75-83%; limited to lesions within 10 cm of anal verge

• CT: 48-72-92%, better for more extensive regional spread; 25-73% for lymph node involvement

• MR: 74-84-93% with tendency for overstaging

• Transrectal ultrasound: 64-77-94% with tendency for overstaging; limited to lesions <14 cm from anal verge + nonstenotic lesions; 50-83% sensitivity for lymph node involvement

Transrectal US (81% accuracy):

Normal layers:

• hyperechoic interface of balloon + mucosa

• hypoechoic mucosa + muscularis mucosa

• hyperechoic submucosa

• hypoechoic muscularis propria

• hyperechoic serosa

• hypoechoic mass disrupting rectal wall:

  • no interruption of hyperechoic submucosa = tumor confined to mucosa + submucosa

  • no interruption of hyperechoic serosa = tumor confined to rectal wall

  • break in outermost hyperechoic layer = tumor penetrates into perirectal fat

  • irregular serrated outer border of muscularis propria (pseudopodia through serosa)

• hypoechoic perirectal lymph nodes (= tumor involvement)

Colonic Volvulus

• = most common form of volvulus

Incidence:

10% of large-bowel obstruction

Cecal Volvulus

• = VOLVULUS OF CECUM

Incidence:	40% of colonic volvulus
Cause:	sudden distension by trauma, pressure, constipation, distal colonic obstruction
Associated with:	malrotation + long mesentery resulting in poor fixation of right colon (10-25% of population)

Pathophysiology of vascular compromise:

• Acute mesenteric torsion + strangulation causes arterial + venous obstruction

• Gradual distension + increase in intraluminal pressure interferes with blood supply; perforation in 65%

Age peak:

20 40 years; M > F

• cecal gaseous distension:

  • cecum rotates anterior to ascending colon =cecal bascule [French = seesaw] (type I cecal volvulus)

  • kidney-shaped distended cecum rotates into left upper quadrant (type II cecal volvulus)

• tapered end of barium column points toward torsion

Cx:

(1) cecal distension >10 12 cm means risk of bowel perforation/infarction
(2) Abdominal compartment syndrome= increase in abdominal pressure diminishes respiratory function + cardiac output

P.816

Sigmoid Volvulus

• = VOLVULUS OF SIGMOID

Cause:	sigmoid twists on mesenteric axis
Age:	usually in elderly/psychiatrically disturbed
Degree of torsion:	360 (50%), 180 (35%), 540 (10%)

• greatly distended paralyzed loop with fluid-fluid levels, mainly on left side, extending toward diaphragm (erect film)

• coffee-bean sign = distinct midline crease corresponding to mesenteric root in largely gas-distended loop (supine)

• bird-of-prey sign = tapered hooklike end of barium column

CT:

• whirl sign = tightly torsioned mesentery formed by twisted afferent + efferent loop

Congenital Esophageal Atresia & Tracheoesophageal Fistula

• = complex of congenital anomalies characterized by failed/incomplete formation of the tubular esophagus or an abnormal communication between esophagus + trachea

Cause:

developmental disorder in formation and separation of primitive foregut into trachea + esophagus/vascular compromise

Embryology:

• primitive foregut tube develops lateral wall folds that may incompletely connect at any point leaving a fistulous communication; occurs at 3rd 5th week of intrauterine life

Incidence:	1:2,000 4,000 livebirths; most common sporadic congenital anomaly diagnosed in childhood
Risk of recurrence in sibling:	1%

Associated anomalies (17 56 70%):

• Gastrointestinal (20 25%): imperforate anus, pyloric stenosis, duodenal atresia, annular pancreas

• Cardiac (15 39%): patent ductus arteriosus, ASD, VSD, right-sided aortic arch (5%)

• Musculoskeletal (24%): radial ray hypoplasia, vertebral anomalies

• Genitourinary (12%): unilateral renal agenesis

• Chromosomal (3 19%): trisomy 18, 21, 13

  • Trisomy 18 is present in 75 100% of fetuses + in 3 4% of neonates with esophageal atresia!

mnemonic:

ARTICLES

• Anal atresia

• Renal anomalies

• TE fistula

• Intestinal atresia/malrotation

• Cardiac anomaly (PDA, VSD)

• Limb anomalies (radial ray hypoplasia, polydactyly)

• Esophageal atresia

• Spinal anomalies

mnemonic:

VACTERL

• Vertebral anomalies

• Anorectal anomaly

• Cardiovascular anomalies

• Tracheo-

• Esophageal fistula

• Renal anomalies

• Limb anomalies

• drooling from excessive accumulation of pharyngeal secretions (esophageal atresia = EA)

• obligatory regurgitation of ingested fluids (EA)

• aspiration with coughing + choking during feeding (TEF)

• recurrent pneumonia + progressive respiratory distress of variable severity (tracheoesophageal fistula = TEF) in neonate

Location:

between upper 1/3 + lower 1/3 of esophagus just above carina

• @ Mediastinum

  • coiled tube = inability to pass feeding tube into stomach (esophageal atresia)

  • retrotracheal air-distended pouch of proximal esophagus causing compression/displacement of trachea

  • non-/hypoperistaltic esophageal segment (6 15 cm) in midesophagus

  • food impaction

• @ Abdomen

  • gasless abdomen (esophageal atresia proximal TE fistula = types A + B)

  • abdomen distended by bowel gas in 90% (distal TE fistula/H-type fistula = types C + D)

• @ Chest

  • bronchopneumonia with patchy airspace opacity, esp. in dependent upper lobes (in 50%)

OB-US (anomalies not identified before 24 weeks GA):

• polyhydramnios in 33 60%:

  • TE-fistula with esophageal atresia is cause of polyhydramnios in only 3%!

• absence of fluid-distended stomach (in 10 41%; in remaining cases TE-fistula/gastric secretions allow some gastric distension)

• reduced intraluminal fluid in fetal gut

• small abdomen (birth weight <10th percentile in 40%)

• distended proximal pouch of atretic esophagus

Cx after repair:

• Anastomotic leak

• Recurrent TE fistula

• Aspiration pneumonia secondary to

  • esophageal stricture

  • disordered esophageal motility distal to TE fistula

  • gastroesophageal reflux

DDx:

pharyngeal pseudodiverticulum (traumatic perforation of posterior pharynx from finger insertion into oropharynx during delivery/tube insertion)

Esophageal Atresia without Fistula = Type A

Frequency:

8 10%

• Associated anomalies in 17% (mostly Down syndrome + other atresias of GI tract)

Esophageal Atresia with Fistula

Associated anomalies in 30% (mostly cardiovascular)

Type B	= esophageal atresia + proximal TE fistula
Frequency:	0.9 1%
Type C	= esophageal atresia + distal TE fistula
Frequency:	53 86%
Type D	= esophageal atresia + proximal and distal TE fistula
Frequency:	1 2.1%

P.817

Tracheoesophageal Fistula without Atresia

Esophageal Atresia With Tracheo-esophageal Fistula

• = H-shaped fistula =Type E

Frequency:

6 10%

Associated anomalies in 23% (mostly cardiovascular)

• feeding difficulties with choking

• diagnosis may not be made for several years

• fistula courses forward and upward from esophagus

mnemonic:	NO PD, P+D No
type A	=esophageal atresia	NO fistula	= 10%
type B	= esophageal atresia	Prox fistula	= 1%
type C	= esophageal atresia	Dist fistula	= 80%
type D	= esophageal atresia	Prox + Dist	= 1%
type E	= H-type fistula	NO atresia	= 10%

Congenital Intestinal Atresia

Incidence:	1:300 livebirths
Cause:	usually sporadic vascular accidents (primary/secondary to volvulus or gastroschisis)
Location:	jejunum + ileum (70%), duodenum (25%), colon (5%); may involve multiple sites

• triple bubble sign = intraluminal gas in stomach + duodenal bulb + proximal jejunum as pathognomonic sign for jejunal atresia

• bulbous bowel segment sign = dilated loop of bowel just proximal to site of atresia (due to prolonged impaction of intestinal contents) with curvilinear termination

• gasless lower abdomen (gut usually air-filled by 4 hours after birth)

• meconium peritonitis (6%)

• polyhydramnios (in 50% with duodenal/proximal jejunal atresia; rarely in ileal/colonic atresia)

Prognosis:

88% survival for isolated atresia

Cricopharyngeal Achalasia

• = hypertrophy of cricopharyngeus muscle (= upper esophageal sphincter) with failure of complete relaxation

Etiology:

• Normal variant without symptoms: seen in 5 10% of adults

• Compensatory mechanism to gastroesophageal reflux

• Neuromuscular dysfunction of deglutition

  • primary neural disorders: brainstem disorder (bulbar poliomyelitis, syringomyelia, multiple sclerosis, amyotrophic lateral sclerosis); central/peripheral nerve palsy; cerebrovascular occlusive disease; Huntington chorea

  • primary muscle disorder: myotonic dystrophy; polymyositis; dermatomyositis; sarcoidosis; myopathies secondary to steroids/thyroid dysfunction; oculopharyngeal myopathy

  • myoneural junction disorder: myasthenia gravis; diphtheria; tetanus

• mostly asymptomatic

• dysphagia

• Cineradiography/videotape recording required for demonstration!

• distension of proximal esophagus + pharynx

• smoothly outlined shelf-/liplike projection posteriorly at level of cricoid (= pharyngoesophageal junction) = level of C5-6

• barium may overflow into larynx + trachea

Cx:	Zenker diverticula
Rx:	cricopharyngeal myotomy

Cowden Disease

• = MULTIPLE HAMARTOMA SYNDROME

• = autosomal dominant disease with high penetrance characterized by multiple hamartomas + neoplasms of endodermal, ectodermal, mesodermal origin

Incidence:	160 cases reported
Cause:	susceptibility gene on long arm of chromosome 10 (10q23)
Age:	2nd decade

• @ Mucocutaneous tumors

  • facial papules

  • oral papillomas (lips, gingiva, tongue)

  • palmoplantar keratosis, acral keratosis

P.818




• @ CNS neoplasia

  • meningioma; glioma

    Associated with:

    dysplastic cerebellar gangliocytoma

  • macrocephaly

• @ Breast lesions (in 50%):

  • fibrocystic disease + fibroadenomas

  • breast cancer (20 30%): often bilateral + ductal

• @ GI tract

  • multiple hamartomatous polyps (in 30 60%, commonly in rectosigmoid)

• @ Thyroid abnormalities (in 60 70%):

  • adenomas + goiter

  • follicular thyroid adenocarcinoma (3 4%)

• @ Genitourinary lesions

• @ Skeletal abnormalities

Crohn Disease

• [Burrill Crohn (1884 1983), gastroenterologist in New York, USA]

• = REGIONAL ENTERITIS

• = disease with prolonged + unpredictable course characterized by discontinuous + asymmetric involvement of entire GI tract

Genetic susceptibility:

• homozygosity for Nod-2 gene (intracellular protein in lymphocytes) responsible for binding bacterial endotoxins + initiating a cascade that produces TNF-alpha;(tumor necrosis factor-alpha)

• increased mucosal permeability for enteric bacteria

Prevalence:	2 3:100,000 white adults
Path:	transmural inflammation (noncaseating granuloma with Langhans giant cells and epithelioid cells, edema, fibrosis); obstructive lymphedema + enlargement of submucosal lymphoid follicles; ulceration of mucosa overlying lymphoid follicles
Age:	onset between 15 and 30 years; M:F = 1:1

• recurrent episodes of diarrhea

• colicky/steady abdominal pain

• low-grade fever

• weight loss, anorexia

• occult blood + anemia

• perianal abscess/fistula (40%)

• malabsorption (30%)

Associated with:	erythema nodosum, pyoderma gangrenosum
Rx:	probiotics + antibiotics (modulation of enteric flora); purine synthesis inhibitors like azathioprine + 6-mercaptopurine (downregulation of inflammatory response); infliximab (chimeric antibody binding to TNF- )

Intestinal Manifestations of Crohn Disease

• @ Esophagus (3%)

  • aphthous ulcers (early)

  • esophagitis, stricture, fistula (late)

• @ Stomach (1 2%) = granulomatous gastritis

  • aphthous ulcers (= pinpoint erosions)

  • pseudo post Billroth-I appearance

  • ram's horn sign = poorly distensible smooth tubular narrowed antrum + widened pylorus + narrow duodenal bulb

  • cobblestone appearance of mucosa

  • antral-duodenal fistula

• @ Duodenum (4 10%)

  • almost always associated with gastric involvement

  Location:

  duodenal bulb + proximal half of duodenum

  • superficial erosions/aphthoid ulcers (early lesion)

  • thickened duodenal folds

• @ Small bowel (80%) = REGIONAL ENTERITIS

  • terminal ileum (alone/in combination in 95%); jejunum/ileum (15 55%)

  • thickening + slight nodularity of circular folds

  • aphthous ulcers

  • cobblestone mucosa/ulceration

  • commonly associated with medial cecal defect

• @ Colon (22 55%) = GRANULOMATOUS COLITIS

  Location:

  particularly on right side with rectum + sigmoid frequently spared

  • tiny 1 2-mm nodular filling defects (lymphoid follicular pattern)

  • aphthous ulcers with target/bull's-eye appearance

  • transverse stripe sign = 1-cm-long straight stripes representing contrast medium within deep grooves of coarse mucosal folds

  • long fistulous tracts parallel to bowel lumen

• @ Appendicitis (20%)

• @ Rectum (14 50%)

  • deep/collarbutton ulcers

  • rectal sinus tracts

Phases:

• Earliest changes

  • nodular enlargement of lymphoid follicles

  • blunting/flattening/distortion/straightening/thickening of valvulae conniventes (obstructive lymphedema, usually first seen in terminal ileum)

  • aphthous ulcers = nodules with shallow central barium collection up to 5 mm in diameter

  Location:

  duodenal bulb, second portion of duodenum, terminal ileum

• Advanced nonstenotic phase

  • skip lesions (90%) = discontinuous involvement with intervening normal areas

  • cobblestone appearance = serpiginous longitudinal + transverse ulcers separated by areas of edema

  • thick + blunted small bowel folds (inflammatory infiltration of lamina propria + submucosa)

  • straightening + rigidity of small bowel loops with luminal narrowing (spasm + submucosal edema)

  • separation + displacement of small bowel loops (from lymphedematous wall thickening/increase in mesenteric fat/enlarged mesenteric lymph nodes/perforation with abscess formation)

  • pseudopolyps = islands of hyperplastic mucosa between denuded mucosa

  • inflammatory polypoid masses

  • sessile/pedunculated/filiform postinflammatory polyps

  • diffuse mucosal granularity due to 0.5 1-mm round lucencies (= blunted + fused villi seen en face)

  • linear ulcers on mesenteric border (nearly PATHOGNOMONIC)

  P.819

  
  

  • pseudodiverticula = pseudosacculations = bulging area of normal wall opposite affected scarred wall on antimesenteric side

• Stenotic phase

  • string sign = strictures (in 21%, most frequently in terminal ileum)/marked narrowing of rigid loops

  • normal proximal loops may be dilated with stasis ulcers + fecoliths

CT:

• @ bowel wall:

  • mucosal hyperenhancement (best seen with bowel lumen distended by negative contrast material):

    • target sign of active inflammation = mural stratification = hyperenhancement of mucosa + muscularis propria sandwiching an edematous/fatty submucosa of decreased attenuation

    • comb sign = hyperemic engorged tortuous vasa recta leading to actively inflamed bowel segment

  • homogeneous density of thickened bowel wall (DDx: ulcerative colitis with heterogeneous attenuation):

    • double halo configuration (50%) = intestinal lumen surrounded by inner ring of low attenuation (= edematous mucosa) + outer ring of soft-tissue density (= thickened fibrotic muscularis + serosa) (DDx: radiation enteritis, ischemia, mesenteric venous thrombosis, acute pancreatitis)

    • skip areas of asymmetric bowel wall thickening of 11 (range 10 20) mm in 82% (DDx: ulcerative colitis with a mean thickness of 8 mm)

  • luminal narrowing + proximal dilatation

• @ paraenteric findings

  • creeping fat = massive proliferation of mesenteric fat along mesenteric border (40%):

    • fat attenuation elevated by 20 60 HU

    • separation of small bowel loops (mass effect)

  • mild mesenteric adenopathy (18%) with lymph nodes 3 8 mm small

    • Consider lymphoma/carcinoma with lymph nodes >10 mm!

  • fistula/sinus tract (15 40%)

  • mesenteric phlegmon/abscess in 15 20% (DDx: postoperative blind loop)

US:

• pseudokidney /target sign = thickening of bowel wall (22 65 89%) of 5 20 mm (DDx: ulcerative colitis)

• circumferential diffusely hypoechoic bowel wall with loss of normal layering (due to transmural edema, inflammation, fibrosis)

• rigid + noncompressible bowel segment with reduction/loss of peristalsis

• hyperemia of gut wall + adjacent fat on color Doppler

• inflammatory mass = phlegmon (14%), abscess (4%)

• distended fluid-filled loops (12%)

• hypoechoic fistulous tract

Prognosis:	recurrence rate of up to 39% after resection (commonly at the site of the new terminal ileum, most frequently during first 2 years after resection); mortality rate of 7% at 5 years, 12% at 10 years after 1st resection
Cx:	(1) Fistula (2) Intramural sinus tracts (3) Abscess in up to 20% (DDx: acute appendicitis) (4) Free perforation (1 2%) (5) Toxic megacolon (6) Small bowel obstruction (15%) (7) Hydronephrosis (from ureteric compression, generally on right side) (8) Adenocarcinoma in ileum/colon (particularly in bypassed loops/in vicinity of chronic fistula) 4 20 increased risk of colonic adeno-carcinoma compared with general population with a latency period of 25 30 years! (9) Lymphoma in large + small bowel
DDx:	(1) Yersinia (in terminal ileum, resolution within 3 4 months) (2) Tuberculosis (more severe involvement of cecum, pulmonary TB) (3) Actinomycosis, histoplasmosis, blastomycosis, anisakiasis (4) Segmental infarction (acute onset, elderly patient) (5) Radiation ileitis (appropriate history) (6) Lymphoma (no spasm, luminal narrowing is uncommon, tumor nodules) (7) Carcinoid tumor (tumor nodules) (8) Eosinophilic gastroenteritis (9) Potassium stricture

Fistulizing Crohn Disease

Incidence:

33%

• Crohn disease is 3rd most common cause of fistula/sinus tracts (DDx: iatrogenic [most common cause], diverticula [2nd most common cause])!

Types:

• enterocolic:

  • most frequently between ileum and cecum

• enterocutaneous (8 21%):

  • rectum-to-skin; rectum-to-vagina

• perineal fistula + sinus tracts

Park's Classification Of Perianal Fistulas

P.820

Extraintestinal Manifestations of Crohn Disease

• @ Hepatobiliary

  • Fatty infiltration of liver (steroid therapy, hyperalimentation)

  • Hepatic abscess (rare): M:F = 3:1

  • Gallstones (15 34%): predominantly cholesterol;

    Risk:	3 5 higher risk than expected; risk correlates with length of diseased ileum/resected ileum/duration of disease
    Cause:	interrupted enterohepatic circulation with malabsorption of bile salts in terminal ileum

  • Acute cholecystitis

  • Primary sclerosing cholangitis (1%) + hepatoma

  • Bile duct + gallbladder carcinoma

  • Pancreatitis

• @ Genitourinary

  • Urolithiasis (5 10%): oxalate (steatorrhea leads to excess colonic absorption of oxalate)/urate stones

  • Hydronephrosis

  • Renal amyloidosis

  • Focal cystitis

  • Ileoureteral/ileovesical fistula (5 20%)

• @ Musculoskeletal

  • digital clubbing (11 40%)

  • mild self-limiting seronegative peripheral migratory arthritis (15 22%): may precede bowel disease in 10%; severity + course correlates well with severity of intestinal disease; resection of diseased bowel leads to regression of symptoms

  • Hypertrophic osteoarthropathy

  • Ankylosing spondylitis (in 3 16%)

    • Axial skeletal involvement usually precedes onset of GI symptoms!

    • unrelated in severity/course to activity level of bowel disease

    • symmetric bilateral sacroiliitis

    • spondylitis with syndesmophytes

  • Peripheral erosive arthritis

    • small marginal erosions

    • periostitis

    • propensity for osseous ankylosis

  • Avascular necrosis of femoral head (steroid Rx)

  • Pelvic osteomyelitis (contiguous involvement)

  • Septic arthritis

  • Muscle abscess

  • Retarded skeletal growth + maturation

• @ Erythema nodosum, uveitis

Cronkhite-Canada Syndrome

• = nonneoplastic nonhereditary polyps (as in juvenile polyposis) associated with ectodermal abnormalities; no familial predisposition

Incidence:	>100 cases described
Histo:	hamartomatous polyps resembling juvenile/retention polyps = multiple cystic spaces filled with mucin secondary to degenerative changes; expansion + inflammation of lamina propria
Age:	62 years (range 42 75 years); M < F

• exudative protein-losing enteropathy

• diarrhea (disaccharidase deficiency, bacterial overgrowth in small intestine)

• severe weight loss, anorexia

• abdominal pain

• nail atrophy

• brownish macules of hand + feet

• alopecia

• multiple polyps

• thickened gastric rugae

Location:	stomach (100%); small bowel (>50%); colon (100%)
Prognosis:	rapidly fatal in women within 6 18 months (cachexia); tendency toward remission in men

Desmoplastic Small Round Cell Tumor

• = INTRAABDOMINAL DESMOPLASTIC SMALL ROUND CELL TUMOR OF PERITONEUM

• = highly malignant tumor belonging to a generic group of small round blue cell tumors (Ewing sarcoma, neuroblastoma, Wilms tumor, rhabdomyosarcoma, primitive neuroendocrine tumor)

Incidence:	<50 cases in literature
Median age:	21 years; affects children + young adults; up to 6th decade; M:F = 4:1
Origin:	mesothelial/submesothelial/subserosal mesenchyme of the abdominal cavity
Histo:	islands of small blue cells surrounded by fibrous stroma; immunohistochemically positive for epithelial, neural, muscular markers (cytoplasmic keratin + desmin); abnormal chromosome 11

• gastrointestinal/genitourinary discomfort/pain

• abdominal distension

• palpable abdominal mass

Location:

mesentery (spread to omentum), retroperitoneum, paratesticular, posterior mediastinum, pleura, meninges

• multiple scattered necrotic tumor masses in abdomen + pelvis with no definite visceral organ of origin:

  • nodular peritoneal thickening

  • serosal hepatic metastases

  • punctate peritoneal calcifications

• enlarged lymph nodes

• scant ascites

Cx:	hydronephrosis, bowel obstruction
Prognosis:	mean survival time of 17 months

DDx:

• in infants/adolescents: rhabdomyosarcoma; neuroblastoma; mesenteric carcinoid; Burkitt lymphoma

• in adults: diffuse omental/peritoneal carcinomatosis (carcinoma of stomach, colon, ovary, pancreas); melanoma; leiomyosarcoma; lymphoma; desmoid tumor; mesothelioma; tumefactive tuberculosis; actinomycosis; Castleman disease

Diaphragm Disease

• = small bowel webs due to NSAIDs

Effect of NSAID:	gastric irritation, ulceration of small intestines
Frequency:	in 10% of patients receiving long-term NSAID therapy
Path:	foci of submucosal fibrosis with interruption of adjacent muscularis mucosae

• blood + protein loss

• intermittent intestinal obstruction

Location:

ileum > jejunum

P.821

Enteroclysis:

• multiple concentric diaphragm-like strictures

DDx:

Crohn disease

Disaccharidase Deficiency

• = enzyme deficiencies for any of the disaccharides (maltose, lactose, etc.)

• PRIMARY

• SECONDARY to other diseases (eg, Crohn disease)

Pathophysiology:

• unabsorbed disaccharides produce osmotic diarrhea

• bacterial fermentation produces short-chain volatile fatty acids causing further osmotic + irritant diarrhea

• normal small bowel series without added lactose

• abnormal small bowel series done with lactose (50 g added to 600 cm³ of barium suspension)

• small + large bowel distension

• dilution of barium

• shortening of transit time

Distal Intestinal Obstruction Syndrome

• = MECONIUM ILEUS EQUIVALENT

• = impaction of inspissated stool in distal part of ileum + proximal part of colon

Prevalence:	7 15 41% of children/adolescents with cystic fibrosis; 2% in patients <5 years of age
Cause:	tenacious intestinal mucus, steatorrhea due to pancreatic insufficiency, undigested food residue, disordered intestinal motility with increase in intestinal transit time, fecal stasis, dehydration
Age:	2nd 3rd decade of life

• recurrent bouts of colicky abdominal pain (from fecal impaction/constipation) in RLQ

• palpable cecal mass

• bubbly granular ileocecal soft-tissue mass in RLQ

• partial/complete small bowel obstruction (due to puttylike fecal material in terminal ileum/right colon)

• thickening of mucosal folds

• cystic fibrosis of lung

Cross Section Through Colon

CT:

Location:

cecum > ascending colon > transverse colon > descending colon (contiguous involvement)

• diffuse colonic thickening

• mural striation (50%)

• mesenteric soft-tissue infiltration (100%)

• increased pericolonic fat (60%)

Cx:	intussusception, volvulus
Rx:	stool softeners, oral polyethylene glycol-electrolyte solution (Golytely ), increasing dose of pancreatic enzyme supplements, mucolytic agents (N-acetylcysteine) orally/with Gastrografin enema
DDx:	appendicitis, partial intestinal obstruction (adhesion/stricture from previous bowel surgery)

Diverticular Disease of Colon

• = overactivity of smooth muscle causing herniation of mucosa + submucosa through muscle layers

Incidence:	5 10% in 5th decade; 33 48% over age 50; 50 65% past 7th decade; M:F = 1:1; most common affliction of colon in developed countries
Cause:	decreased fecal bulk (diet high in refined fiber + low in roughage)
Location:	in 80% in sigmoid (= narrowest colonic segment with highest pressure); in 17% distributed over entire colon; in 4 12% isolated to cecum/ascending colon

Prediverticular Disease of Colon

• = longitudinal + circular smooth muscle thickening with redundancy of folds secondary to myostatic contracture

• saw-tooth sign = crowding + thickening of haustral folds (shortening of colonic segment)

• plump marginal indentations

• superimposed muscle spasm (relieved by antispasmodics)

DDx:

hemorrhage; ischemia; radiation changes; pseudomembranous colitis

Colonic Diverticulosis

• = acquired herniations of mucosa + muscularis mucosae through the muscularis propria with wall components of mucosa, submucosa, serosa = false diverticula of pulsion type

Location:

predominantly left-sided colon

Site:

• lateral diverticula arise between mesenteric + antimesenteric teniae on opposite sides

• antimesenteric intertaenial diverticula opposite of mesenteric side

• Intramural type vasa recta (= nutrient arteries) pass through the circular muscle (weakness in muscular wall) and are carried over the fundus of the diverticula as it enlarges

• size: initially tiny (3 10-mm) V-shaped protrusions increasing up to several cm in diameter

• bubbly appearance of air-containing diverticula

• residual barium within diverticula from previous study

P.822




• spiky irregular outline (antimesenteric intertaenial ridge is typical site for intramural diverticula)

• smooth dome-shaped appendages with a short neck

• may be pointed, attenuated, irregular with variable filling

• circular line with sharp outer edge + fuzzy blurred inner edge (en face view in double contrast BE)

• Giant sigmoid diverticulum = large gas-containing cyst (air entrapment secondary to ball-valve mechanism) arising in left iliac fossa

CT:

• rounded outpouchings containing air contrast material (= diverticula)

• circumferential sawtooth-like thickening of colonic haustra + distorted luminal contour (= muscular hypertrophy)

Cx:

bleeding (usually right colon), diverticulitis (usually sigmoid colon)

Colonic Diverticulitis

• = perforation of diverticulum with intramural/localized pericolic inflammatory mass

Incidence:	5% of population; in 10 35% of diverticular disease; increasing frequency with age (in 5 10% >45 years of age, in 80% >85 years of age)
Pathogenesis:	mucosal abrasion from inspissated fecal material leads to perforation of thin wall

• pain + local tenderness + mass in LLQ

• fever (25%), leukocytosis (36%)

• clinical misdiagnosis rate of 34 67%

Location:

sigmoid colon (95%), cecum (4%)

• localized ileus

• pattern of small bowel obstruction (kinking/edema if small bowel adheres to abscess)

• extraluminal gas in abscess/fistula

• pneumoperitoneum (rare)

BE (77 86% sensitive):

• focal area of eccentric luminal narrowing caused by pericolic/intramural inflammatory mass:

  • annular lesion mimicking carcinoma

• marked thickening + distortion of mucosal folds

• tethered spiculated mucosal folds

• centrally amputated diverticulum

• extraluminal contrast = peridiverticulitis:

  • double-tracking = pericolonic longitudinal sinus tract

  • pericolonic collection = peridiverticular abscess

  • fistula to bladder/small bowel/vagina

CT (79 93% sensitive, 77% specific):

• inflamed diverticulum:

  • pericolic fat stranding = poorly marginated hazy area of increased attenuation fine linear strands within pericolic fat (98%)

  • diverticula (84%) = flask-shaped structures projecting through colonic wall + filled with air/barium/fecal material

  • centipede sign = hyperemic engorged vasa recta

• bowel wall thickening:

  • circumferential bowel wall thickening of >4 mm (70%)

  • focally thickened + inflamed colonic wall

  • arrowhead sign = funnel of intraluminal contrast medium/air in focally thickened colonic wall centering about occluded orifice of inflamed diverticulum (27%)

• fluid collection:

  • frank abscess (47%) = central liquid/gas

  • fluid air of peritonitis (16%)

  • fluid at root of sigmoid mesentery

• tract formation:

  • fistula formation (14%): most commonly colovesical, also colovaginal, coloenteric, colocutaneous

  • intramural sinus tracts (9%)

• fecolith

• colonic obstruction (12%)

• ureteral obstruction (7%)

US (85 98% sensitive, 80 97% specific):

• thickening of bowel wall = >4 mm distance between echogenic lumen interface and serosa

• diverticula = round/oval hypo-/hyperechoic foci protruding from colonic wall with focal disruption of normal layer continuity internal acoustic shadowing

• inflammatory pericolic fat = regionally increased echogenicity adjacent to colonic wall ill-defined hypoechoic zones

• pericolic abscess

Prognosis:	(a) self-limiting (usually) (b) transmural perforation (c) superficial ulceration (d) chronic abscess
Cx:	(1) Colonic obstruction (2) Fistula to bladder/vagina/small bowel (3) Free perforation (rare)
DDx:	(1) Colonic neoplasm (shorter segment, heaped-up margins, ulcerated mucosa) (2) Crohn colitis (double-tracking longer than 10 cm)
Rx:	antibiotics, surgery (in 25%), percutaneous abscess drainage

Right Colonic Diverticulitis

• = congenital true diverticulum

Frequency:	1:34 1:300 appendectomies
Age:	any; peak prevalence at 35 45 years of age

• protracted mild pain; palpable mass in 33%

• solitary diverticulum containing a 12-mm fecolith surrounded by inflamed fat

• marked circumferential colonic wall thickening

Cx:	pericolonic abscess
Prognosis:	spontaneous evacuation into colonic lumen
Rx:	conservative
DDx:	appendicitis

Colonic Diverticular Hemorrhage

• Not related to diverticulitis

Incidence:	in 3 47% of diverticulosis
Location:	75% located in ascending colon (larger neck + dome of diverticula)

• massive rectal hemorrhage without pain

• extravasation of radionuclide tracers

• angiographic contrast pooling in bowel lumen

Rx:

(1) transcatheter infusion of vasoconstrictive agents (Pitressin )
(2) embolization with Gelfoam

P.823

Dumping Syndrome

• = early postprandial vascular symptomatology of sweating, flushing, palpitation, feeling of weakness and dizziness

Pathophysiology:	rapid entering of hypertonic solution into jejunum resulting in fluid shift from blood compartment into small bowel
Incidence:	1 5%; M:F = 2:1

• Roentgenologic findings not diagnostic!

• rapid emptying of barium into small bowel (= loss of gastric reservoir function)

Rx:	lying down, diet
DDx:	late postprandial hypoglycemia (90 120 minutes after eating)

Duodenal Atresia

• = most common cause of congenital duodenal obstruction; second most common site of gastrointestinal atresias after ileum

Incidence:	1:10,000; M:F = 1:1
Etiology:	defective vacuolization of duodenum between 6th and 11th weeks of fetal life; rarely from vascular insult (extent of obstruction usually involves larger regions with vascular insult)
Age at presentation:	first few days of life

• persistent bilious vomiting a few hours after birth/following 1st feeding (75%)

• rapid deterioration secondary to loss of fluids + electrolytes

• Isolated sporadic anomaly (30 52%)

Associated anomalies (in 50 60%):

• Down syndrome (20 33%);

  • 25% of fetuses with duodenal atresia have Down syndrome!

  • <5% of fetuses with Down syndrome have duodenal atresia!

• CHD (8 30 50%): endocardial cushion defect, VSD

• Gastrointestinal anomalies (26%):

  • esophageal atresia, biliary atresia, duodenal duplication, imperforate anus, small bowel atresia, malrotation, Ladd bands, Meckel diverticulum, transposed liver, annular pancreas (20%), preduodenal portal vein

• Urinary tract anomalies (8%)

• Vertebral + rib anomalies (37%)

Location:

(a) usually distal to ampulla of Vater (80%)
(b) proximal duodenum (20%)

• double bubble sign = gas-fluid levels in duodenal bulb + gastric fundus

• total absence of intestinal gas in small/large bowel

• colon of normal caliber

OB-US (usually not identified prior to 24 weeks GA):

• elevated AFP

• double bubble sign = simultaneous distension of stomach + 1st portion of duodenum, continuity of fluid between stomach + duodenum must be demonstrated

• increased gastric peristalsis

• polyhydramnios in 3rd trimester (100%)

Prognosis:	36% mortality in neonates
DDx:	(1) Prominent incisura angularis causing bidissection of stomach (2) Choledochal cyst (3) Annular pancreas (4) Peritoneal bands (5) Intestinal duplication
Cx:	prematurity (40%) secondary to preterm labor related to polyhydramnios

Duodenal Diverticula

Duodenal Diverticulum

Incidence:

1 5% of GI studies; 22% of autopsies

• PRIMARY DIVERTICULUM

  • = mucosal prolapse through muscularis propria

  • posteriorly (8%), lateral wall (4%)

• SECONDARY DIVERTICULUM

  • = all layers of duodenal wall = true diverticulum as complication of duodenal/periduodenal inflammation

Location:

almost invariably in 1st portion of duodenum

• mostly asymptomatic

Cx:

(1) Perforation + peritonitis
(2) Bowel obstruction
(3) Biliary obstruction
(4) Bleeding
(5) Diverticulitis

Duodenal Ulcer

Incidence:	200,000 cases/year; 2 3 more frequent than gastric ulcers; M:F = 3:1
Pathophysiology:	too much acid in duodenum from (a) abnormally high gastric secretion (b) inadequate neutralization
Predisposed:	cortisone therapy, severe cerebral injury, after surgery, chronic obstructive pulmonary disease

Location:

• bulbar (95%):

  • anterior wall (50%), posterior wall (23%), inferior wall (22%), superior wall (5%)

  • bulbar deformity in 85%

• postbulbar (3 5%):

  • M:F = 7:1; majority on medial wall above papilla

  • hemorrhage in 66%

  • edema + spasm may obscure ulcer

  • smooth rounded indentation of lateral wall

• frequently <1 cm round/ovoid (5% linear) ulcer niche

• kissing ulcers = ulcers opposite from each other on anterior + posterior wall

P.824




• giant duodenal ulcer >2 cm (rare) with higher morbidity + mortality; may be overlooked by simulating a normal/deformed scarred duodenal bulb

• cloverleaf deformity, hourglass stenosis (healed stage) with prestenotic dilatation of recesses

Cx:	(1) Obstruction (5%) (2) Perforation (<10%): anterior > posterior wall; fistula to gallbladder (3) Penetration (<5%) = sealed perforation (4) Hemorrhage (15%): melena > hematemesis
Rx:	antral resection (Billroth I) + vagotomy

Duodenal Varices

• = dilated collateral veins secondary to portal hypertension (posterior superior pancreaticoduodenal vein)

• lobulated filling defects (best demonstrated in prone position, maximal luminal distension will obliterate them)

• commonly associated with fundal + esophageal varices

Duplication Cyst

• = uncommon congenital anomaly found anywhere along alimentary tract from tongue to anus

Incidence:

15% of pediatric abdominal masses are gastrointestinal duplication cysts

Theories of formation:

• Abortive twinning

• Persistent embryologic diverticula

• Split notochord

• Aberrant luminal recanalization (Bremer): foregut epithelium grows and obliterates lumen (solid stage for esophagus, small bowel, colon); later produces secretions that form vacuoles in the intercellular space; vacuoles line up longitudinally and coalesce to form new lumen; failure of an aberrant vacuole to coalesce creates a wall cyst

• Intrauterine vascular accident (Favara) associated with alimentary tract atresia in 9%

Age:	presentation often in infancy/early childhood
Path:	spherical cyst/tubular structure located in/immediately adjacent to gastrointestinal tract; shares a common muscle wall + blood supply; has a separate mucosal lining; cyst contents are usually serous
Histo:	smooth muscle wall + lined with alimentary tract mucosa; ectopic mucosa; squamous, transitional, ciliated mucosa; lymphoid aggregates; ganglion cells Gastric mucosa + pancreatic tissue are the only ectopic tissues of clinical importance!

• respiratory distress (with esophageal duplication)

• palpable abdominal mass

• nausea, emesis (due to partial/complete obstruction)

Location:	ileum (30 33%), esophagus (17 20%), colon (13 30%), jejunum (10 13%), stomach (7%), pylorus (4%), duodenum (4 5%), ileocecal junction (4%), rectum (4%) In 7 15% concomitant duplications elsewhere in the alimentary tract!
Site:	on mesenteric aspect of alimentary canal

Morphology:

• large spherical/saccular cyst (82%)

• small intramural cyst

• tubular sausage-shaped cyst (18%): commonly along small + large bowel; frequently communicates with lumen of adjacent gut

BE:

• mass extrinsic to bowel lumen

US:

• elongated tubular/spherical cystic mass:

  • sonolucent mass with good through transmission (due to clear fluid content)

  • echogenic mass (due to hemorrhage + inspissated material)

• muscular rim sign (= echogenic inner mucosal lining + hypoechoic outer rim) in 47%

• cyst paralleling normal bowel lumen

CT:

• smoothly rounded fluid-filled cyst/tubular structure

• thin slightly enhancing wall

MR:

• heterogeneous signal intensity of intracystic fluid on T1WI + homogeneous high signal intensity on T2WI

Cx:

bowel obstruction, intussusception (due to cyst at ileocecal junction), small bowel volvulus (due to weight of duplication), bleeding (due to presence of gastric mucosa/pressure necrosis of adjacent mucosa by cyst expansion/from intussusception)

DDx:

• Omental cyst (greater omentum/lesser sac, multilocular)

• Mesenteric cyst (between leaves of small bowel mesentery)

• Choledochal cyst

• Ovarian cyst

• Pancreatic pseudocyst

• Cystic renal tumor

• Abscess

• Meckel diverticulum (communicates with GI tract)

• Lymphangioma

• Mesenteric lymphoma

• Intramural tumor

Colonic Duplication Cyst

Incidence:

13% of all alimentary tract duplications

Cystic Colonic Duplication (7%)

Path:

closed spherical cyst; contains gastric mucosa in 2% + ectopic pancreatic tissue in 5%

• abdominal mass, bowel obstruction/constipation

• GI hemorrhage

Location:

cecum (40%) intussusception

• air/intestinal matter can enter cyst (20%)

Colorectal Tubular Duplication (6%)

• = DUPLICATION OF THE HINDGUT

• = double-barreled duplication involving part/all of large bowel with twin segment on mesenteric/antimesenteric side

Symptomatic age:

neonatal period/infancy; M:F = 1:2

May be associated with:

• rectogenital/rectourinary fistula, duplication of internal/external genitalia, vertebral anomalies, multisystem congenital anomaly complex

• bowel obstruction/constipation

P.825




• passage of feces through vagina

• simultaneous opacification of true + twin colon

• duplication may terminate at

  • 2nd functional anus

  • imperforate perineal orifice

  • fistulous communication with GU tract

Double Appendix

Duodenal Duplication Cyst

Incidence:	5% of all alimentary tract duplications
Path:	noncommunicating spherical cyst; may contain ectopic gastric mucosa in 21%, small bowel mucosa, pancreatic tissue

• obstructive symptoms, palpable abdominal mass

• hemorrhage (due to peptic ulceration)

• jaundice (due to biliary obstruction)

• pancreatitis (due to ectopic pancreatic tissue)

Site:

on mesenteric side of anterior wall of 1st + 2nd portion of duodenum

• mass in concavity of duodenal C-loop

• compression + displacement of 1st/2nd portion of duodenum superiorly + anteriorly

Cholangiography:

• may communicate with pancreatic ductal system through the aberrant duct of an accessory lobe

Cx:	pancreatitis from perforation of duplication cyst
DDx:	pancreatic cyst, pancreatic pseudocyst, choledochal cyst, choledochocele, duodenal intramural tumor, pancreatic tumor

Esophageal Duplication Cyst

• arises from foregut

Incidence:	10 20% of all alimentary tract duplications; 0.5 2.5% of all esophageal masses; M:F = 2:1
Path:	contains ectopic gastric mucosa in 43%
Histo:	contains no cartilage, lined by alimentary tract mucosa
Associated with:	vertebral anomalies (spina bifida, hemivertebra, fusion defects), esophageal atresia, small bowel duplication (18%)
Location:	adjacent to esophagus/within esophageal musculature at any level, paraspinal position; R:L = 2:1; in right pleural space detached from esophagus (rare)

• CERVICAL ESOPHAGUS (23%)

  • asymptomatic enlarging lateral neck mass

  • upper airway obstruction in newborn

  DDx:

  thyroglossal duct cyst, branchial cleft cyst, cystic hygroma, cervical tumor, cervical lymphadenopathy

• MIDESOPHAGUS (17%)

  • severe upper airway obstruction in early infancy

  DDx:

  bronchogenic cyst, neurenteric cyst, intramural esophageal tumor

• DISTAL ESOPHAGUS (60%)

  • frequently asymptomatic

  Location:	paraspinal
  DDx:	bronchogenic cyst, neurenteric cyst, intramural esophageal tumor

  • thick-walled closed spherical cyst, almost never communicating

CXR:

• posterior mediastinal mass air-fluid level

• lobar consolidation + central cavitation (from autodigestion of lung tissue by gastric secretions)

• thoracic vertebral anomalies

UGI:

• displacement of esophagus by paraesophageal mass

• intramural extramucosal mass

US:

• hypoechoic fluid-filled cyst + inner mucosal lining

CT:

• sharply marginated homogeneous near-water density mass without enhancement

Cx:

(1) Peptic ulceration (secondary to gastric mucosa)
(2) Perforation (secondary to penetrating ulcer)
(3) Hematemesis (from erosion into esophagus)
(4) Hemoptysis + autodigestion of pulmonary tissue (from erosion into tracheobronchial tree)

Gastric Duplication Cyst

• = intramural gastric cyst lined with secretory epithelium

Incidence:	7% of all alimentary tract duplications
Path:	noncommunicating spherical cyst (majority); may communicate with aberrant pancreatic duct; ectopic pancreatic tissue found in 37%
Symptomatic age:	infancy; in 75% detected before age 12; M:F = 1:2

• pain (from overdistension of cyst, rupture with peritonitis, peptic ulcer formation, internal pancreatitis)

• vomiting, anemia, fever

• symptoms mimicking congenital hypertrophic pyloric stenosis (if duplication in antrum/pylorus)

Most common site:

greater curvature (65%)

• paragastric cystic mass up to 12 cm in size, indenting greater curvature

• seldom communicates with main gastric lumen at one or both ends

• may enlarge + ulcerate

• Tc-99m uptake

US:

• cyst with two wall layers: inner echogenic layer of mucosa + outer hypoechoic layer of muscle

• clear/debris-containing fluid

Cx:	(1) Partial/complete small bowel obstruction (2) Relapsing pancreatitis (with ductal communication) (3) Ulceration, perforation, fistula formation
DDx:	pancreatic cyst, pancreatic pseudocyst, mesenteric cyst, leiomyoma, adenomatous polyp, hamartoma, lipoma, neurofibroma, teratoma

Rectal Duplication Cyst

Incidence:	4% of all alimentary tract duplications
Path:	spherical fluid-filled cyst; may contain duodenal/gastric mucosa + pancreatic tissue
Site:	posterior to rectum/anus

• communication with rectum/perianal fistula (in 20%)

Symptomatic age:

childhood

P.826

• constipation + fecal soiling

• palpable retrorectal/retroanal mass

• intractable excoriation of perianal skin (with chronic perianal fistula)

• cystic mass; may be echogenic (due to solid material gas from communication with rectum)

DDx:

anterior meningocele, sacrococcygeal teratoma, retrorectal abscess, pilonidal cyst, sacral bone tumor

Small Bowel Duplication Cyst

Incidence:	most common of all alimentary tract duplications
Symptomatic age:	neonatal period (1/3); <2 years of age (in 72%)
Path:	contains ectopic gastric mucosa in 24%; ectopic pancreatic tissue in jejunum (8%)
May be associated with:	small bowel atresia

• neonatal bowel obstruction

• intussusception, palpable mass

• acute abdominal pain

• GI hemorrhage (may be painless)

Location:	ileum (33%), jejunum (10%), ileocecal (4%)
Site:	on mesenteric side

• low small bowel obstruction soft-tissue mass

• cyst may serve as lead point for intussusception

DDx:

mesenteric cyst, pancreatic pseudocyst, omental cyst, exophytic hepatic cyst, ovarian cyst

Thoracoabdominal Duplication

• = FOREGUT DUPLICATION

• = long tubular cyst closed at its cranial end, passing through diaphragm through its own hiatus, in 60% communicating with normal duodenum/jejunum/ileum

Incidence:	2% of all alimentary tract duplications
Associated with:	thoracic vertebral anomalies
Histo:	gastric mucosa in 29%
Symptomatic age:	50% during neonatal period; 80% within 1st year of life

• severe respiratory distress

• chest pain, GI bleeding, anemia

• tubular right posterior mediastinal mass air

• thoracic vertebral anomaly

• contrast material may enter through distal connection

Ectopic Pancreas

• = PANCREATIC REST = MYOEPITHELIAL HAMARTOMA

Incidence:

2 10% of autopsies; M:F = 2:1

• asymptomatic

Location:

lesions may be multiple
(a) greater curvature of antrum 1 6 cm from pylorus, pylorus, duodenal bulb, proximal jejunum (in 80%)
(b) ileum, Meckel diverticulum

• smooth cone-/nipple-shaped submucosal nodule 1 5 cm in size

• central umbilication representing orifice of filiform duct

Enteric Cyst

• = cyst lined by gastrointestinal mucosa without bowel wall

Etiology:	migration of small bowel/colonic diverticulum into mesentery/mesocolon
Path:	unilocular thin smooth-walled cyst with serous contents lined by enteric epithelium + thin fibrous wall

US:

• hypoechoic cystic mass, occasionally with septations

DDx:

duplication cyst (reduplication of bowel wall)

Eosinophilic Gastroenteritis

• = uncommon self-limited form of gastroenteritis with remissions + exacerbations characterized by infiltration of eosinophilic leukocytes into stomach/small bowel wall + usually marked peripheral eosinophilia

Cause:	unknown
Histo:	fibrous tissue + eosinophilic infiltrate of gastrointestinal mucosa
Age:	in children + young adults with allergy + eosinophilia

• EOSINOPHILIC GRANULOMA

  • = FIBROUS POLYPOID LESION

  • = INFLAMMATORY PSEUDOTUMOR

  • = localized form/circumscribed type

    Location:

    almost exclusively in stomach (most common in antrum + pylorus)

  • submucosal polypoid mass/pedunculated polyp

• EOSINOPHILIC GASTROENTERITIS

  • = diffuse type

  • = eosinophilic infiltration of mucosa, submucosa, and muscular layers of small intestine stomach by mature eosinophils ( gastric pendant to L ffler syndrome)

• recurrent episodes of abdominal pain, diarrhea, vomiting

• weight loss

• hematemesis (from ulceration)

• peripheral eosinophilia, anemia

• history of systemic allergy/food allergy

Location:	entire small bowel (particularly jejunum), distal stomach, omentum, mesentery
Site:	(a) mucosal (b) muscular (c) serosal (rare)

• @ Stomach (almost always limited to antrum)

  • wet stomach

  • ulcers are rare

  • mucosal type

    • enlarged gastric rugae/cobblestone nodules/polyps

  • muscular type

    • thickened + rigid wall with narrowed gastric antrum/pylorus

    • bulky intraluminal mass up to 9 cm in size

    Cx:	pyloric obstruction
    DDx:	hypertrophic gastritis, lymphoma, carcinoma

• @ Small bowel (involved in 50%)

  • separation of small bowel loops

  • mucosal type

    • malabsorption + hypoproteinemia

    • thickening + distortion of folds predominantly in jejunum

  • submucosal/muscular type

    • motility disturbance

    • small-bowel obstruction

    • effacement of mucosal pattern + narrowing of lumen

  • serosal type

    • ascites

P.827

Prognosis:	tendency toward spontaneous remission
Rx:	steroids/removal of sensitizing agent

Epiploic Appendagitis

• = rare inflammation of one of the 100 epiploic/omental appendages, between 5 and 50 mm long, arising from serosal surface of colon

Cause:	(a) primary: torsion (exercise), venous thrombosis (b) secondary: inflammation of adjacent organ (eg, diverticulitis, appendicitis)
Associated with:	obesity, hernia, unaccustomed exercise
Age:	4th 5th decade; M>F
Histo:	acute infarction with fat necrosis, inflammation, thrombosed vessels with hemorrhagic suffusion

• abrupt onset of localized abdominal pain (RLQ in 50%), gradually resolving over 3 7 days

• palpable mass (10 30%)

• peritoneal signs

• normal/mildly increased WBCs; NO fever

• Almost never suspected preoperatively!

Location:

anterolaterally/(occasionally) anteromedially to sigmoid > descending > ascending colon

US:

• solid hyperechoic noncompressible oval mass at site of maximal tenderness

• hypoechoic margin (93%)

• absence of central blood flow

CT:

• pericolic oval-shaped pedunculated mass, 1 5 cm in diameter, with fat attenuation (approx. 60 HU):

  • hyperattenuating peripheral rim

  • internal fat stranding

• periappendigeal fat infiltration

• thickening of adjacent visceral peritoneal lining (93%)

MR:

• foal lesion with signal intensity of fat

• enhancing rim

Cx:	adhesion, bowel obstruction, intussusception, intraperitoneal loose body, peritonitis, abscess
Prognosis:	spontaneous resolution within 2 weeks clinically + within 6 months on CT
Rx:	conservative management with NSAID
DDx:	torsion/infarction of greater omentum, sclerosing mesenteritis, diverticulitis, appendicitis, primary tumor of mesocolon

Esophageal Cancer

Incidence:	<1% of all cancers; 4 10% of all GI malignancies; 11,000 cases/year (USA in 1994); M:F = 4:1; Blacks:Whites = 2:1
High-risk regions:	Iran, parts of Africa, Italy, China

Predisposing factors:

• achalasia (risk factor of 1,000 x), asbestosis, Barrett esophagus, celiac disease, radiation exposure, caustic stricture (risk factor of 1,000 x), Plummer-Vinson syndrome, tannins, alcohol, tobacco, history of oral/pharyngeal cancer, tylosis palmaris et plantaris

mnemonic:

BELCH SPAT

• Barrett esophagus

• EtOH abuse

• Lye stricture

• Celiac disease

• Head and neck tumor

• Smoking

• Plummer-Vinson syndrome

• Achalasia, Asbestosis

• Tylosis

Cancer Staging:

• TNM system:

  T1	tumor invades lamina propria/submucosa
  T2	tumor invades muscularis propria
  T3	tumor invades adventitia
  T4	tumor invades adjacent structures

  Stage I	= T1,N0,M0
  Stage IIA	= T2/3,N0,M0
  Stage IIB	= T1/2,N1,M0
  Stage III	= T3,N1,M0 or T4,N0/1,M0
  Stage IV	= T1-4,N0/1,M1

• CT staging (Moss):

  Stage 1	intraluminal tumor/localized wall thickening of 3 5 mm
  Stage 2	localized/circumferential wall thickening >5 mm
  Stage 3	contiguous spread into adjacent mediastinum (trachea, bronchi, aorta, pericardium) loss of fat planes (nonspecific due to cachexia, often still resectable) mass in contact with aorta >90 arc (in 20 70% still resectable) displacement/compression of airway (90 100% accuracy for invasion) esophagotracheal/-bronchial fistula (unresectable)
  Stage 4	distant metastases enlarged abdominal lymph nodes >10 mm (12 85% accuracy) hepatic, pulmonary, adrenal metastases direct erosion of vertebral body tumor >3 cm wide = high frequency of extraesophageal spread

Histo:

• Squamous cell carcinoma (50 70%)

• Adenocarcinoma (30 50%) arising from mucosal/submucosal glands or heterotopic gastric mucosa or columnar-lined epithelium (Barrett)

  • in 70% from Barrett esophagus

  • gastric adenocarcinoma involving GE junction

  • in submucosal/deep esophageal glands

  • ectopic gastric mucosa in esophagus

  • 2,500 new cases each year; M:F = 7:1

  • tendency to invade gastric cardia + fundus

• Spindle-cell squamous carcinoma = carcinosarcoma = pseudosarcoma

  Histo:	squamous + sarcomatous elements
  Age:	in men >45 years
  Location:	usually middle third of esophagus

  • large bulky polypoid smooth, lobulated, scalloped intraluminal mass; may be pedunculated

  DDx:

  lymphoma, other sarcomas

• Mucoepidermoid ca., adenoid cystic carcinoma

• Leiomyosarcoma, rhabdomyosarcoma, fibrosarcoma, malignant lymphoma

P.828




• Secondary tumor involvement from: thyroid, larynx

• Metastasis from: breast, melanoma, GI tract

• dysphagia (87 95%) of <6 months' duration

• weight loss (71%)

• retrosternal pain (46%)

• regurgitation (29%)

Location:

upper 1/3 (15 20%); middle 1/3 (37 44%); lower 1/3 (38 43%)

Radiologic types:

• Polypoid/fungating form (most common)

  • sessile/pedunculated tumor with lobulated surface

  • protruding, irregular, polycyclic, overhanging, steplike apple core lesion

• Ulcerating form

  • large ulcer niche within bulging mass

• Infiltrating form

  • gradual narrowing with smooth transition

  • (DDx: benign stricture)

• Varicoid form = superficial spreading carcinoma

  Histo:

  longitudinal extension confined to mucosa/submucosa

  • focal area of confluent mucosal nodules/plaques

  DDx:

  Candida esophagitis

Metastases:

• lymphogenic: anterior jugular chain + supraclavicular nodes (primary in upper 1/3); paraesophageal + subdiaphragmatic nodes (primary in middle 1/3); mediastinal + paracardial + celiac trunk nodes (primary in lower 1/3)

• hematogenous: lung, liver, adrenal gland

CXR:

• widened azygoesophageal recess with convexity toward right lung (in 30% of distal + midesophageal cancers)

• thickening of posterior tracheal stripe + right paratracheal stripe >4 mm (if tumor located in upper third of esophagus)

• widened mediastinum

• tracheal deviation

• posterior tracheal indentation/mass

• retrocardiac mass

• esophageal air-fluid level

• lobulated mass extending into gastric air bubble

• repeated aspiration pneumonia (with tracheoesophageal fistula)

Cx:	fistula formation to trachea (5 10%)/bronchi/mediastinum
Prognosis:	3 5 20% 5-year survival rate; 0% 5-year survival rate for cancer of cervical esophagus

Mean survival time:

• 90 days with subdiaphragmatic lymphadenopathy

• 180 days with local invasion + abdominal metastases

• 480 days without evidence of invasion/metastases

Rx:	(1) chemotherapy (fluorouracil, cisplatin, bleomycin sulfate, mitomycin) + surgery (2) chemotherapy + irradiation (~4,000 cGy) (3) chemotherapy + irradiation + surgery
Operative mortality:	3 8%

Esophageal Intramural Pseudodiverticulosis

• = dilated excretory ducts of deep mucous glands

Etiology:	uncertain
Incidence:	about 100 cases in world literature

In 90% associated with:

• diabetes, alcoholism, any severe esophagitis (most often reflux/Candida), esophageal stricture

Site:

diffuse/segmental involvement

• multiple tiny rounded/flask-shaped barium collections in longitudinal rows parallel to long axis of esophagus:

  • appear to float outside esophagus without apparent communication with lumen

• esophageal stricture:

  • short stricture in distal esophagus (common)

  • long stricture in cervical/upper thoracic esophagus (classic)

Esophageal Perforation

• = ESOPHAGEAL RUPTURE

Cause:

• Iatrogenic injury (most common cause, 55%): complication of endoscopy, dilatation of stricture, bougie, disruption of suture line following surgical anastomosis, attempted intubation

• Spontaneous rupture = Boerhaave syndrome (15%): emetogenic injury of the esophagus from sudden increase in intraabdominal pressure + relaxation of distal esophageal sphincter in the presence of a moderate to large amount of gastric contents

• Closed chest trauma (10%)

  Incidence:

  1% of all blunt chest trauma

  • Location:

    • cervical/upper thoracic esophagus (82%)

    • just above gastroesophageal junction along posterolateral wall on the left side

• Esophageal carcinoma

• Retained foreign body (14%): coin, aluminum pop-tops, metallic button, safety pin, invisible plastic toy) leading to perforation (in pediatric age group)

• Barrett ulcer

• pain, dysphagia, odynophagia

• rapid onset of overwhelming sepsis: fever, tachycardia, hypotension, shock

Plain film (normal in 9 12%):

• extensive pneumomediastinum

• V sign of Naclerio = extrapleural air within lower mediastinum between parietal pleura + diaphragm (usually on left)

• subcutaneous emphysema of the neck

• delayed widening of the mediastinum (secondary to mediastinitis)

• hydrothorax (after rupture into pleural cavity), usually unilateral on left side

• hydropneumothorax (often not initially seen)

• left lower lobe atelectasis

• confirmation with contrast study (90% of contrast esophagograms are positive)

CT:

• focal extraluminal air collection at site of tear (92%; most useful sign)

• periesophageal/mediastinal hematoma/fluid (92%)

• pleural effusion (75%)

P.829




• esophageal wall thickening

• extravasation of oral contrast material

Esophagography with:

• water-soluble contrast material (10% false-negative results)

• barium (if result with water-soluble material negative)

Cx:	(1) Acute mediastinitis (2) Obstruction of SVC (3) Mediastinal abscess
Prognosis:	20 60% mortality

Upper/Midesophageal Perforation

Location:

at level of cricopharyngeus muscle (most frequent)

• widening of upper mediastinum

• right-sided hydrothorax

Distal Esophageal Perforation

Incidence:	more common (but not in blunt chest trauma)
Cause:	biopsy, dilatation of stricture, Boerhaave syndrome

• left-sided hydrothorax

• little mediastinal changes

Esophageal Varices

• = plexuses formed by dilated subepithelial veins + submucosal veins + dilated venae commitantes of the vagus nerves outside the tunica muscularis

Anatomy:

• anterior branch connected to left gastric vein

• posterior branch connected to azygos + hemiazygos system

Examination Technique:

• small amount of barium (not to obscure varices)

• relaxation of esophagus (not to compress varices): refrain from swallowing because succeeding swallow initiates a primary peristaltic wave that lasts for 10 30 seconds; sustained Valsalva maneuver precludes from swallowing

• in LAO projection with patient recumbent/in Trendelenburg position Valsalva maneuver/deep inspiration

Plain film:

• lobulated masses in posterior mediastinum (visible in 5 8% of patients with varices)

• silhouetting of descending aorta

• abnormal convex contour of azygoesophageal recess at level of gastroesophageal junction

UGI:

• thickened sinuous interrupted mucosal folds (earliest sign)

• tortuous radiolucencies of variable size + location

• worm-eaten smooth lobulated filling defects

• findings may be accentuated after sclerotherapy

CT:

• thickened esophageal wall + lobulated outer contour

• scalloped esophageal luminal masses

• right-/left-sided soft-tissue masses (= paraesophageal varices)

• marked enhancement following dynamic CT

Cx:	bleeding in 28% within 3 years; exsanguination in 10 15%
DDx:	varicoid carcinoma of esophagus

Uphill Esophageal Varices

• = collateral blood flow from portal vein via azygos vein into SVC (usually lower esophagus drains via left gastric vein into portal vein)

Cause:

• intrahepatic obstruction from cirrhosis

  • In <5% of patients with portal hypertension

• splenic vein thrombosis (usually gastric varices)

• obstruction of hepatic veins

• IVC obstruction below hepatic veins

• IVC obstruction above hepatic vein entrance/CHF

• marked splenomegaly/splenic hemangiomatosis (rare)

• varices in lower half of esophagus

Downhill Esophageal Varices

• = collateral blood flow from SVC via azygos vein into IVC/portal venous system (upper esophagus usually drains via azygos vein into SVC)

Cause:

obstruction of superior vena cava distal to entry of azygos vein (= superior vena cava syndrome) most commonly due to lung cancer, lymphoma, retrosternal goiter, thymoma, mediastinal fibrosis

• varices in upper 1/3 of esophagus

Esophageal Web

• = complete/incomplete circumferential narrowing caused by 1 2-mm thick (vertical length) mucosal membrane projecting into esophageal lumen; covered by squamous epithelium on superior + inferior surfaces

Age:

middle-aged females

Association with:

• Plummer-Vinson syndrome = Paterson-Kelly syndrome (iron deficiency anemia, stomatitis, glossitis, dysphagia, thyroid disorder, spoon-shaped nails)

Cause:

mnemonic:

BIEP

• B-ring (Schatzki ring)

• Idiopathic (= transverse mucosal fold)

• Epidermolysis bullosa

• Plummer-Vinson disease

Path:

hyperkeratosis + chronic inflammation of submucosa

• mostly asymptomatic (unless severely stenosing)

Location:

in cervical esophagus near cricopharyngeus (most common) > thoracic esophagus; occasionally multiple

• visualized during maximal distension (in one-tenth of a second)

• arises at right angles from anterior esophageal wall

• thin delicate membrane of uniform thickness of <3 mm

Cx:	high risk of upper esophageal + hypopharyngeal carcinoma
Rx:	(1) balloon dilatation (2) bougienage during esophagoscopy
DDx:	stricture (circumferential + thicker = 1 2-mm thick [vertical length] area of complete/incomplete circumferential narrowing

P.830

Esophagitis

Acute Esophagitis

Cause:

mnemonic:

CRIER

• Corrosives, Crohn disease

• Reflux

• Infection, Intubation

• Epidermolysis bullosa

• Radiation therapy

• thickened >3-mm-wide folds with irregular lobulated contour

• mucosal nodularity (= multiple ulcerations + intervening edema)

• erosions

• vertically oriented ulcers usually 3 10 mm in length

• inflammatory esophagogastric polyp = proximal gastric fold extending across esophagogastric junction (rare)

• abnormal motility

Candida Esophagitis

• = MONILIASIS = CANDIDIASIS

• Most common cause of infectious esophagitis!

Organism:

C. albicans, C. tropicalis; endogenous (majority)/transmitted by another human/animal; often discovered in diseased skin, GI tract, sputum, female genital tract, urine with an indwelling Foley catheter

Predisposed:

• individuals with depressed immunity: hematologic disease, renal transplant, leukemia, chronic debilitating disease, diabetes mellitus, steroids, chemotherapy, radiotherapy, AIDS

  • Most common type of fungi found with opportunistic infections!

• delayed esophageal emptying: scleroderma, strictures, achalasia, S/P fundoplication

• antibiotics

Path:	patchy, creamy-white plaques covering a friable erythematous mucosa
Histo:	mucosal plaques = necrotic epithelial debris + fungal colonies

• dysphagia (= difficulty swallowing)

• severe odynophagia (= painful swallowing from segmental spasm)

• intense retro-/substernal pain

• associated with thrush (= oropharyngeal moniliasis) in 20 50 80%

Location:

predilection for upper 1/2 of esophagus

• involvement of long esophageal segments:

  • cobblestone appearance = mucosal nodularity in early stage (from growth of colonies on surface)

  • longitudinal plaques = grouping of tiny 1 2-mm nodular filling defects with linear orientation (= heaped-up areas of mucosal plaques)

  • shaggy/fuzzy/serrated contour (from coalescent plaques, pseudomembranes, erosions, ulcerations, intramural hemorrhage) in fulminant candidiasis of AIDS

• narrowed lumen (from spasm, pseudomembranes, marked edema)

• intramural diverticulosis = multiple tiny indentations + protrusions

• sluggish/absent primary peristalsis

• strictures (rare)

• mycetoma resembling large intraluminal tumor (rare)

Diagnostic sensitivity:	endoscopy (97%), double contrast (88%), single contrast (55%)
Cx:	(1) Systemic candidiasis ( microabscesses in liver, spleen, kidney) (2) Gastric bezoar due to large fungus ball (after long-standing esophageal candidiasis)
Rx:	ketoconazole/fluconazole
DDx:	glycogen acanthosis, reflux esophagitis, superficial spreading carcinoma, artifacts (undissolved effervescent crystals, air bubbles, retained food particles), herpes esophagitis, acute caustic ingestion, intramural pseudo-diverticulosis, squamous papillomatosis, Barrett esophagus, epidermolysis bullosa, varices

Caustic Esophagitis

• = CORROSIVE ESOPHAGITIS

Corrosive agents:

• lye (sodium hydroxide), washing soda (sodium carbonate), household cleaners, iodine, silver nitrate, household bleaches, Clinitest tablets (tend to be neutralized by gastric acid)

  • Severity of injury dependent on contact time + concentration of corrosive material!

Associated with:	injury to pharynx + stomach (7 8%): antral burns more common with acid (buffering effect of gastric acid on alkali)
Location:	middle + lower thirds of esophagus
Stage I:	acute necrosis from protein coagulation mucosal blurring (edema) diffusely atonic + dilated esophagus tertiary contractions/spasm
Stage II:	frank ulceration in 3 5 days ulceration + pseudomembranes
Stage III:	scarring + stricture from fibroblastic activity long segmental stricture after 10 days when acute edema subsides (7 30%)
Cx:	(1) Esophageal/gastric perforation during ulcerative stage (2) Squamous cell carcinoma in injured segment
Rx:	dilatation procedure/esophageal replacement surgery

Chronic Esophagitis

• luminal narrowing with tapered transition to normal + proximal dilatation

• circumferential/eccentric stricture

• sacculations = pseudodiverticula

Drug-induced Esophagitis

• = contact esophagitis due to oral medications = pill esophagitis

Agents:

antibiotics (tetracycline, doxycycline), quinidine, potassium chloride, nonsteroidal antiinflammatory agents (aspirin), ascorbic acid, alprenolol chloride, emepronium bromide, alendronate (= inhibitor of osteoclastic activity)

P.831

• severe odynophagia

• history of taking medication with little/no water immediately before going to bed

• rapid clinical improvement after withdrawal of offending agent

Location:

midesophagus at site of normal extrinsic impressions by aortic arch/left mainstem bronchus/left atrium

• localized cluster of tiny ulcers distributed circumferentially (most commonly)

• superficial solitary/several discrete ulcers

Prognosis:	ulcers heal within 7 10 days after cessation of offending medication
DDx:	herpes esophagitis (immunosuppressed patient, less localized); reflux esophagitis (heartburn, distal esophagus near esophagogastric junction)

Reflux Esophagitis

• = esophageal inflammation secondary to reflux of acid-peptic contents of the stomach; reflux occurs if resting pressure of LES <5 mm Hg (may be normal event if followed by rapid clearing)

Prevalence:	in 20% of gastroesophageal reflux
Histo:	basal cell hyperplasia with wall thickening + thinning of epithelium, mucosal edema + erosions, inflammatory infiltrate
Determinants:	(1) Frequency of reflux (2) Adequacy of clearing mechanism (3) Volume of refluxed material (4) Potency of refluxed material (5) Tissue resistance

Reflux preventing features:

• Lower esophageal sphincter

• Phrenoesophageal membrane

• Length of subdiaphragmatic esophagus

• Gastroesophageal angle of His (70 110 )

May be associated with:

sliding hiatal hernia (in most patients), scleroderma, nasogastric intubation

• heartburn, epigastric discomfort

• choking, globus hystericus

• retrosternal pain

• thoracic/cervical dysphagia

Site:

usually lower 1/3/lower 1/2 with continuous disease extending proximally from GE junction

• segmental esophageal narrowing (edema/spasm/stricture)

• poorly defined tiny mucosal elevations ( mucosal granularity ) on thickened/nodular longitudinal folds (mucosal edema + inflammation) in early stages

• single marginal ulcer/erosion at or adjacent to gastroesophageal junction

• multiple areas of superficial ulceration in distal esophagus

• prominent mucosal fold ending in polypoid protuberance within hiatal hernia/cardia

• interruption of primary peristalsis at inflamed segment

• nonperistaltic waves in distal esophagus following deglutition (85%)

• incomplete relaxation of LES (75%), incompetent sphincter (33%)

• acid test = abnormal motility elicited by acid barium (pH 1.7)

• felinization = transverse ridges of esophagus secondary to contraction of muscularis mucosae (similar to cat esophagus)

NUC (pertechnetate):

• esophageal activity (Barrett esophagus similar to ectopic gastric mucosa)

Reflux tests:

• Reflux of barium in RPO position, may be elicited by coughing/deep respiratory movements/swallowing of saliva + water/anteflexion in erect position: only in 50% accurate

• Water-siphon test: in 5% false negative; large number of false positives

• Tuttle test = measurement of esophageal pH: 96% accurate

• Radionuclide gastroesophageal reflux test (typically combined with gastric emptying test):

  Technique:

  ROI drawn over distal esophagus + compared with time-activity curve over stomach, scaled to 4%

  • esophageal activity >4% stomach activity

Cx of reflux:

• from acid + pepsin acting on esophageal mucosa:

  • Motility disturbance

  • Stricture

  • Schatzki ring

  • Barrett esophagus

  • Iron-deficiency anemia

  • Reflux/peptic esophagitis

• from aspiration of gastric contents

  • Acute aspiration pneumonia

  • Mendelson syndrome

  • Pulmonary fibrosis

Viral Esophagitis

Predisposed:

immunocompromised, eg, underlying malignancy, debilitating illness, radiation treatment, steroids, chemotherapy, AIDS

Cytomegalovirus Esophagitis

Organism:	member of herpesvirus group
Associated with:	AIDS

• severe odynophagia

• diffusely normal mucosal background

• one/more giant ovoid flat ulcers (up to several cm in size) near gastroesophageal junction

• discrete small superficial ulcers indistinguishable from herpes esophagitis (uncommon)

Rx:	ganciclovir (relatively toxic)
Dx:	endoscopic brushings, biopsy specimen, cultures

Herpes Esophagitis

• 2nd most common cause of opportunistic infection!

Organism:	Herpes simplex virus type I (DNA core virus) secreted in saliva of 2% of healthy population
Age:	15 30 years; usually males
Predisposed:	immunosuppressed patient

• history of recent exposure to sexual partners with herpetic lesions on lips/buccal mucosa

P.832




• flulike prodrome of 3 10 days (headaches, fever, sore throat, upper respiratory symptoms, myalgia)

• severe acute dysphagia/odynophagia

May be associated with:	oropharyngeal herpetic lesions/oropharyngeal candidiasis
Location:	midesophagus (level of left main bronchus)

• initially vesicles/blisters that subsequently rupture

• multiple small discrete superficial punctate/round/linear/serpentine/stellate (often diamond-shaped ) ulcers surrounded by radiolucent halos of edematous mucosa (in >50%)

• intervening mucosa normal (without plaques)

• multiple plaquelike lesions (only with severe infection)

Dx:	rising serum titer for HSV type I, viral culture, biopsy (immunofluorescent staining for HSV antigen, demonstration of intranuclear inclusions)
Rx:	oral/intravenous acyclovir
Prognosis:	resolution of symptoms in 3 14 days
DDx:	drug-induced esophagitis, Crohn disease, esophageal intramural pseudodiverticulosis

Human Immunodeficiency Virus Esophagitis

• maculopapular rash + ulcers of soft palate (occasionally)

• recent seroconversion/known AIDS

• one/more giant (>1 cm) flat ovoid/diamond-shaped ulcers (at time of seroconversion) indistinguishable from CMV esophagitis

Dx:	per exclusion (brushings, biopsies, cultures negative for CMV)
Rx:	oral steroids
DDx:	CMV esophagitis, mycobacterial esophagitis, actinomycosis, potassium chloride, quinidine, caustic ingestion, nasogastric intubation, radiation therapy, endoscopic sclerotherapy

Familial Adenomatous Polyposis

• = FAMILIAL MULTIPLE POLYPOSIS

• = autosomal dominant disease with 80% penetrance (gene for familial polyposis localized on chromosome 5); sporadic occurrence in 1/3

Incidence:	1:7,000 to 1:24,000 live births
Histo:	tubular/villotubular adenomatous polyps; usually about 1,000 adenomas
Age:	polyps appear around puberty

• family history of colonic polyps (66%)

  • Screening of family members after puberty!

• clinical symptoms begin during 3rd 4th decade (range 5 55 years)

• vague abdominal pain, weight loss

• diarrhea, bloody stools

• protein-losing enteropathy (occasionally)

Associated with:

(1) Hamartomas of stomach in 49%
(2) Adenomas of duodenum in 25%
(3) Periampullary carcinoma

• carpet of polyps = myriad of 2 3 mm (up to 2 cm) polypoid lesions

• @ Colon (100%): more numerous in distal colon; always affecting rectum

  • normal haustral pattern

• @ Stomach (5%)

• @ Small bowel (<5%)

Cx:	malignant transformation of adenomas in: colon > stomach > small bowel (in 12% by 5 years; in 30% by 10 years; in 100% by 20 years after diagnosis; age at carcinomatous development usually 20 40 years; multiple carcinomas in 48%) 331-fold increased risk of small bowel adenocarcinoma compared to general population after colectomy Periampullary carcinoma is the most common cause of death after prophylactic colectomy!
Rx:	prophylactic total colectomy in late teens/early twenties before symptoms develop (1) Permanent ileostomy (2) Continent endorectal pull-through pouch (3) Kock pouch (= distal ileum formed into a one-way valve by invaginating the bowel at skin site)
DDx:	other polyposes, lymphoid hyperplasia, lymphosarcoma, ulcerative colitis with inflammatory pseudopolyps

Gallstone Ileus

Incidence:	0.4 5% of all intestinal obstructions (20% of obstruction in patients >65 years; 24% of obstructions in patients >70 years); develops in <1% of patients with cholelithiasis; in 1 of 6 perforations; risk increases with age
Etiology:	biliary disease (90%), peptic ulcer disease, cancer, trauma
Age:	average 65 75 years; M:F = 1:4 1:7

• previous history of gallbladder disease

• intermittent episodes of acute colicky abdominal pain (20 30%)

• nausea, vomiting, fever, distension, obstipation

• Rigler triad on plain film (in 10%):

  • Partial/complete intestinal obstruction (usually small bowel), string of rosary beads = multiple small amounts of air trapped between dilated + stretched valvulae conniventes (in 86%)

  • Gas in biliary tree (in 69%)

  • Ectopic calcified gallstone (in 25%): stones are commonly >2.5 cm in diameter

• change in position of previously identified gallstone

UGI/BE:

• well-contained localized barium collection lateral to first portion of duodenum (barium-filled collapsed GB + possibly biliary ducts)

  • Fistulous communication:

    • cholecystoduodenal (60%), choledochoduodenal, cholecystocolic, choledochocolic, cholecystogastric

• identification of site of obstruction: terminal ileum (60 70%), proximal ileum (25%), distal ileum (10%), pylorus, sigmoid, duodenum (Bouveret syndrome)

Cx:	recurrent gallstone ileus in 5 10% (additional silent calculi more proximally)
Prognosis:	high mortality

Gangliocytic Paraganglioma

• = rare benign tumor of the GI tract

Frequency:	<100 cases reported
Origin:	pancreatic endocrine rest that remained when the ventral primordium rotated around the duodenum
Age:	50 60 years of age; M:F = 2:1
Location:	almost exclusively in 2nd portion of duodenum near the ampulla of Vater on the medial/lateral wall of duodenum

P.833

• GI hemorrhage, abdominal pain

• polypoid smooth-surfaced intraluminal mass

• homogeneously enhancing mural/extrinsic solid mass of soft-tissue attenuation

• well-circumscribed hypoechoic mass contiguous with bowel

• no biliary duct dilatation

DDx:

adenocarcinoma (biliary duct dilatation, hypovascular), leiomyosarcoma (cystic internal hemorrhage/necrosis), hemangioma, duplication cyst, choledochal cyst, lipoma, hamartoma, inflammatory fibroid polyp (distal small bowel), lymphoma (isolated in stomach and ileum)

Gardner Syndrome

• = autosomal dominant disease ( variant of familial polyposis) characterized by a triad of

  • colonic polyposis

  • osteomas

  • soft-tissue tumors

Cause:	adenomatous polyposis gene on chromosome 5-q21; in 20% new mutations Familial polyposis + Gardner syndrome may occur in the same family!
Histo:	adenomatous polyps
Age:	15 30 years (2 months 70 years)
Associated with:	MEA complex

• periampullary/duodenal carcinoma (12%)

• papillary thyroid carcinoma (often multicentric)

• adrenal adenoma/carcinoma

• parathyroid adenoma

• pituitary chromophobe adenoma

• carcinoid, adenoma of small bowel

• retroperitoneal leiomyoma

• Extraintestinal manifestations occur usually earlier than in intestinal polyposis!

• skin pigmentation

• cramping abdominal pain

• weight loss, diarrhea

• @ Polyposis

  Location:

  colon (100%), stomach (5 68%), duodenum (90%), small bowel (<5%)

  • multiple colonic polyps appearing during puberty, increasing in number during 3rd 4th decade

  • lymphoid hyperplasia of terminal ileum

  • hamartomas of stomach

  • intussusception

  Cx:

  small bowel/colonic obstruction

• @ Soft-tissue tumors

  • sebaceous/epidermoid inclusion cysts (scalp, back, face, extremities)

  • fibroma, lipoma, leiomyoma, neurofibroma

  • desmoid tumors (3 29%); peritoneal adhesions (desmoplastic tendency); mesenteric fibrosis, retroperitoneal fibrosis

    • urinary tract obstruction

  • mammary fibromatosis

  • marked keloid formation, hypertrophied scars (anterior abdominal wall) arise 1 3 years after surgery

• @ Osteomatosis of membranous bone (50%)

  Location:

  calvarium, mandible (81%), maxilla, ribs, long bones

• @ Long bones

  • localized wavy cortical thickening/exostoses

  • slight shortening + bowing

• @ Teeth

  • odontoma, unerupted/supernumerary teeth, hypercementosis

  • tendency toward numerous caries (dental prosthesis at early age)

Cx:	malignant transformation of colonic polyps in 100% (average age at death is 41 years if untreated)
Prophylaxis:	gastrointestinal surveillance, thyroid screening, ophthalmologic evaluation for retinal pigmentation anomalies; screening of family members starting at age 15
Rx:	prophylactic total colectomy at about 20 years of age

Gastric Carcinoma

• 3rd most common GI malignancy after colorectal + pancreatic cancer, 6th leading cause of cancer deaths

Prevalence:	declining; 24,000 cases/year in USA
Risk factors:	smoking, nitrites, nitrates, pickled vegetables

Predisposing factors:

• H. pylori gastritis, chronic atrophic gastritis, adenomatous + villous polyp (7 27% are malignant), gastrojejunostomy, partial gastrectomy (Billroth II > Billroth I), pernicious anemia (risk factor of 2), M n trier disease ( )

Histo:

adenocarcinoma (95%); rarely squamous cell carcinoma/adenoacanthoma

Staging:

T1	tumor limited to mucosa/submucosa
T2	tumor involves muscle/serosa
T3	tumor penetrates through serosa
T4a	invasion of adjacent contiguous tissues
T4b	invasion of adjacent organs, diaphragm, abdominal wall
N1	involvement of perigastric nodes within 3 cm of primary along greater/lesser curvature
N2	involvement of regional nodes >3 cm from primary along branches of celiac axis
N3	paraaortic, hepatoduodenal, retropancreatic, mesenteric nodes
M1	distant metastases

Location:

mostly distal third of stomach + cardia; 60% on lesser curvature, 10% on greater curvature; esophagogastric junction in 30%; transpyloric spread in 5 25% (for lymphoma 40%)

Probability of malignancy of an ulcer:

• at lesser curvature 10 15%, at greater curvature 70%, in fundus 90%

Morphology:

• Polypoid/fungating carcinoma

• Ulcerating/penetrating carcinoma (70%)

• Infiltrating/scirrhous carcinoma (5 15%)

  • = linitis plastica

  Histo:	frequently signet ring cell type + increase in fibrous tissue
  Location:	antrum, fundus + body (38%)

  P.834

  
  

  • firmness, rigidity, reduced capacity of stomach, aperistalsis in involved area

  • granular/polypoid folds with encircling growth

• Superficial spreading carcinoma

  • = confined to mucosa/submucosa; 5-year survival of 90%

  • patch of nodularity

  • little loss of elasticity

• Advanced bulky carcinoma

• GI bleeding, abdominal pain, weight loss

UGI:

• rigidity

• filling defect

• amputation of folds ulceration stenosis

• miliary/punctate calcifications (mucinous adenocarcinoma)

CT:

• irregular nodular luminal surface

• asymmetric thickening of folds

• mass of uniform density/varying attenuation

• wall thickness >6 mm with gas distension + 13 mm with positive contrast material distension:

  • diffuse low attenuation in mucinous carcinoma

• increased density in perigastric fat

• enhancement exclusively in linitis plastica type

• nodules of serosal surface (= dilated surface lymphatics)

• diameter of esophagus at gastroesophageal junction larger than adjacent aorta (DDx: hiatal hernia)

• lymphadenopathy below level of renal pedicle (3%)

Metastases:

• along peritoneal ligaments

  • gastrocolic lig.: transverse colon, pancreas

  • gastrohepatic + hepatoduodenal lig.: liver

• local lymph nodes

• hematogenous: liver (most common), adrenals, ovaries, bone (1.8%), lymphangitic carcinomatosis of lung (rare)

• peritoneal seeding:

  on rectal wall	= Blumer shelf
  on ovaries	= Krukenberg tumor

• left supraclavicular lymph node = Virchow node

Prognosis:

• overall 5-year survival rate of 5 18%, mean survival time of 7 8 months;

85%	5-year survival in stage T1
52%	5-year survival in stage T2
47%	5-year survival in stage T3
17%	5-year survival in stage N1-2
5%	5-year survival in stage N3

Early Gastric Cancer (20%)

• = invasion limited to mucosa + submucosa (T1 lesion) regardless of lymph node involvement

Classification of Japan Research Society for Gastric Cancer:

Type I	protruded type = >5 mm in height with protrusion into gastric lumen (10 20%)
Type II	superficial type = <5 mm in height
IIa	slightly elevated surface (10 20%)
IIb	flat/almost unrecognizable (2%)
IIc	slightly depressed surface (50 60%)
Type III	excavated/ulcerated type (5 10%)

Advanced Gastric Cancer (T2 lesion and higher)

Bormann classification:

Type 1	broad-based elevated polypoid lesion
Type 2	elevated lesion + ulceration + well-demarcated margin
Type 3	elevated lesion + ulceration + ill-defined margin
Type 4	ill-defined flat lesion
Type 5	unclassified, no apparent elevation

Gastric Diverticulum

• Stomach is least common site of diverticula

Incidence:	1:600 2,400 of UGI studies
Etiology:	(a) traction secondary to scarring/periantral inflammation = true diverticulum (b) pulsion (less common) = false diverticulum
Age:	beyond 40 years
Often associated with:	aberrant pancreas in antral location
Location:	juxtacardiac on posterior wall (75%), prepyloric (15 22%), greater curve (3%)

• pliability + varying degrees of distension

• NO mass, edema or rigidity of adjacent folds

DDx:

small ulcer in intramural-extramucosal mass

Gastric Polyp

Incidence:	1.5 5%, most common benign gastric tumor
Associated with:	hyperacidity + ulcers, chronic atrophic gastritis, gastric carcinoma

• NONNEOPLASTIC

  • Inflammatory polyp of stomach (75 90%)

    • = HYPERPLASTIC POLYP = REGENERATIVE POLYP

    Histo:	cystically dilated glands lined by gastric epithelium + acute and chronic inflammatory infiltrates in lamina propria
    Associated with:	chronic atrophic gastritis, pernicious anemia
    Location:	predominantly in fundus + body; usually multiple

    • sharply delineated polyp with smooth circular border

    • Mexican hat sign = stalk seen en face overlying the head of polyp

    • sessile/pedunculated

    • usually <2 cm in diameter without progression

    • no contour defect of stomach

    Prognosis:

    no malignant potential

  • Hamartomatous polyp of stomach (rare)

    Histo:	densely packed gastric glands + bundles of smooth muscle
    Associated with:	Peutz-Jeghers syndrome

    • sessile/pedunculated

    • usually <2 cm in diameter

  • Retention polyp of stomach (rare)

    Histo:	dilated cystic glands + stroma
    Associated with:	Cronkhite-Canada syndrome

• NEOPLASTIC

  • Adenomatous polyp of stomach (10 20%)

    • = true neoplasm with malignant potential (10 80%, increasing with size)

    Age:	increasing incidence with age; M:F = 2:1
    Histo:	intestinal metaplasia (common) + marked cellular atypism
    Associated with:	Gardner syndrome; coexistent with gastric carcinoma in 35%
    Location:	more commonly in antrum (antrum spared in Gardner syndrome)

    P.835

    
    

    • broad-based elliptical/mushroom-shaped polyp pedicle; usually solitary

    • usually >2 cm in diameter (in 80%)

    • smooth/irregular lobulated contour

  • Villous polyp of stomach (rare)

    • trabeculated/lobulated slightly irregular contour

    Cx:

    malignant transformation

DDx:

(1) M n trier disease (antrum spared)
(2) Eosinophilic polyp (peripheral eosinophilia, linitis plastica appearance, small bowel changes)
(3) Lymphoma
(4) Carcinoma

Gastric Ulcer

Benign Gastric Ulcer

• 95% of all gastric ulcers

Cause:

• HORMONAL

  • Zollinger-Ellison syndrome

  • Hyperparathyroidism (in 1.3 24%)

    • duodenum:stomach = 4:1; M:F = 3:1

    • Duodenal ulcers predominate in females!

    • Gastric ulcers predominate in males!

    • absence of gastric hypersecretion

  • Steroid-induced ulcer

    • gastric > duodenal location;

    • frequently multiple + deep ulcers;

    • commonly associated with erosions

    • bleeding (in 1/3)

  • Stress, severe prolonged illness

  • Cerebral disease = Cushing ulcer

  • Curling ulcer (burns) (in 0.09 2.6%)

  • Retained gastric antrum

  • Uremia

• INFLAMMATION

  • Peptic ulcer disease

  • Gastritis

  • Radiation-induced ulcer

  • Intubation

  • Stasis ulcer proximal to pyloric/duodenal obstruction

• BENIGN MASS

  • Leiomyoma

  • Granulomatous disease

  • Pseudolymphoma (lymphoid hyperplasia)

• DRUGS

  ASA:

  greater curvature

Pathophysiology:

• disrupted mucosal barrier (Helicobacter pylori) with vulnerability to acid + secretion of large volume of gastric juice containing little acid

Incidence:	5:10,000; 100,000/year (United States)
Age peak:	55 65 years; M:F = 1:1

Multiplicity:

• multiple in 2 8% (17 24% at autopsy), especially in patients on aspirin

• coexistent duodenal ulcer in 5 64%; gastric:duodenal = 1:3 (adults) = 1:7 (children)

• abdominal pain: in 30% at night, in 25% precipitated by food

Location:

lesser curvature at junction of corpus + antrum within 7 cm from pylorus; proximal half of stomach in older patients (geriatric ulcer); adjacent to GE junction within hiatal hernia

• ulcer size usually <2 cm (range 1 250 mm); in 4% >40 mm

• round/ovoid/linear shape

• Haudek niche = conical/collar button-shaped barium collection projecting outside gastric contour (profile view)

• Hampton line = 1-mm thin straight lucent line traversing the orifice of the ulcer niche (seen on profile view + with little gastric distension) = ledge of touching overhanging gastric mucosa of undermined benign ulcer

• ulcer collar = smooth thick lucent band interposed between the niche and gastric lumen (thickened rim of edematous gastric wall) in well-distended stomach

• ulcer mound = smooth, sharply delineated, gently sloping extensive tissue mass surrounding a benign ulcer (edema + lack of wall distensibility) in well-distended stomach

• ulcer crater = round/oval barium collection with smooth border on dependent side (en face view)

• halo defect = wide lucent band symmetrically surrounding ulcer resembling extensive ulcer mound (viewed en face)

• ring shadow: ulcer on nondependent side (en face view)

• radiating thick folds extending directly to crater edge fusing with the effaced marginal fold of the ulcer collar/halo of ulcer mound

• incisura defect = smooth, deep, narrow, sharp indentation on greater curvature opposite a niche on lesser curvature at/slightly below the level of the ulcer (spastic contraction of circular muscle fibers)

Prognosis:	healing in 50% by 3 weeks, in 100% by 6 8 weeks; slower healing in older patients; only complete healing proves benignancy
Cx:	bleeding, perforation, fistula Most common cause of gastrocolic fistula!

Gastric Ulcer
Sign	Benign	Malignant
Crater	round, ovoid	irregular
Radiating folds	symmetric	nodular, clubbed, fused
Areae gastricae	preserved	destroyed
Projection	outside lumen	inside lumen
Ulcer mound	smooth	rolled edge

Malignant Gastric Ulcer

Incidence:

5% of ulcers are malignant

Cause:

• Gastric carcinoma

• Lymphoma (2% of all gastric neoplasms)

  • multiple ulcers with aneurysmal appearance

P.836




• Leiomyosarcoma, neurogenic sarcoma, fibrosarcoma, liposarcoma

• Metastases

  • hematogenic: malignant melanoma, breast cancer, lung cancer

  • per continuum: pancreas, colon, kidney

Prognosis:	partial healing may occur
Location:	anywhere within stomach; fundal ulcers above level of cardia are usually malignant

• ulcer location within gastric lumen, ie, not projecting beyond expected margin of stomach (profile view)

• eccentrically located ulcer within the tumor

• irregularly shaped ulcer

• shallow ulcer with width greater than depth

• nodular ulcer floor

• abrupt transition between normal mucosa + abnormal tissue at some distance (usually 2 4 cm) from ulcer edge

• rolled/rounded/shouldered edges surrounding ulcer

• nodular irregular folds approaching ulcer with fused/clubbed/amputated tips

• rigidity/lack of distensibility

• associated large irregular mass

• Carman meniscus sign = curvilinear lens-shaped intraluminal form of crater with convexity of crescent toward gastric wall and concavity toward gastric lumen (profile view, usually under compression) found in specific type of ulcerating carcinoma, seen only infrequently; wall aspect can also be concave/flat

• Kirklin meniscus complex = Carman sign (appearance of crater) + radiolucent slightly elevated rolled border

Gastric Varices

Cause:	portal hypertension (varices seen in 2 78%); splenic vein obstruction (from pancreatitis, pancreatic carcinoma, pseudocyst)
Location:	(a) esophagogastric junction (most common) (b) along lesser curvature (in 11 75% of patients with portal hypertension/cirrhosis)

Feeding vessels:

• Left gastric vein (between splenic vein + stomach)

• Short gastric veins (between spleen + fundus)

• Retrogastric vein (between splenic vein + esophagogastric junction)

• increased prevalence of portosystemic encephalopathy

• barium study: 65 89% rate of detection:

  • lobulated folds/polypoid masses in fundus

• endoscopy: most practical method

• splenic portography

• hepatofugal blood flow along SMV into left gastric + splenic vein

Cx:

variceal bleeding in 3 10 36%
Gastric varices bleed less frequently but more severely than esophageal varices!

Gastric Volvulus

• SURGICAL EMERGENCY

• = abnormal degree of rotation of one part of stomach around another part, usually requires >180 twisting to produce complete obstruction

Degrees of rotation:

• Partial Volvulus

  • = rotation of stomach <180 degrees without vascular compromise

• Complete volvulus

  • = rotation of stomach >180 degrees

Etiology:

• abnormality of suspensory ligaments

• unusually long gastrohepatic + gastrocolic mesenteries

Anatomy of ligaments:

• gastrohepatic at lesser curvature; gastrosplenic + gastrocolic at greater curvature; gastrophrenic at posterior fundus; attachment to esophagus at gastroesophageal junction; attachment to duodenum at pylorus

Predisposing factors:

• sliding/paraesophageal hernia (33%), ligamentous laxity, eventration of diaphragm, phrenic nerve paralysis, splenic abnormalities (asplenia, polysplenia, splenomegaly, prior splenectomy)

Age:

40 50 years (in 20% in infants <1 year of age); M:F = 1:1

Types:

• ORGANOAXIAL VOLVULUS (more common)

  • = rotation around a line from cardia to pylorus

  • more common in elderly

  • high correlation with hiatal hernia

  • mirror-image stomach:

    • reversal of locations of greater + lesser curvatures (in transversely oriented stomach)

    • greater curvature to right of lesser curvature (in vertically oriented stomach)

• MESENTEROAXIAL VOLVULUS (less common)

  • = rotation around an axis from lesser to greater curvature coinciding with axis of mesenteric attachments

  • associated with severe obstruction + strangulation

  • upside-down stomach (= antrum + pylorus superior to fundus + proximal body)

• COMBINATION (rare)

• Borchordt triad:

  • sudden onset of severe epigastric pain

  • intractable retching (= vigorous attempts to vomit) without production of vomitus

  • inability to pass nasogastric tube into stomach

• chronic volvulus: asymptomatic/postprandial pain, belching, bloating, vomiting, early satiety

• massively distended stomach in LUQ extending into chest

• unexpected location of stomach gas bubble

• air-fluid levels in mediastinum/upper abdomen

• incomplete/absent entrance of barium into stomach

• displaced gastroesophageal junction

• barium demonstrates area of twist

Cx:	intramural emphysema, gastric ischemia, necrosis, perforation, peritonitis, shock, gastric ulceration, hemorrhage, pancreatic necrosis, omental avulsion, splenic rupture
Mortality:	42 80% in acute volvulus; 10 13% in chronic volvulus
Rx:	open/laparoscopic gastropexy
DDx:	gastric atony, acute gastric dilatation, pyloric obstruction

P.837

Gastritis

Corrosive Gastritis

Agents:

• acid, formaldehyde

  • clinically usually silent

  Location:

  esophagus usually unharmed, severe gastric damage, duodenum may be involved (newer potent materials cause atypical distribution)

• alkaline

  Location:

  pylorus + antrum most frequently involved

• ACUTE CHANGES (edema + mucosal sloughing)

  • marked enlargement of gastric rugae + erosions/ulceration

  • complete cessation of motor activity

  • gas in portal venous system

  Cx:

  perforation

• CHRONIC CHANGES

  • firm thick nonpliable wall

  • stenotic/incontinent pylorus (if involved)

  • gastric outlet obstruction (cicatrization) after 3 10 weeks

Emphysematous Gastritis

• = rare but severe form of widespread phlegmonous gastritis subsequent to mucosal disruption characterized by gas in wall of stomach

Cause of mucosal disruption:

• ingestion of toxic/corrosive substances (37%), alcohol abuse (22%), gastroenteritis (15%), recent abdominal surgery (15%), gastric infarction, necrotizing enterocolitis, ulcer, acute pancreatitis, adenocarcinoma of stomach, phytobezoar, leukemia, diabetes mellitus, disseminated strongyloidiasis, gastric mucormycosis, after ingestion of large amounts of carbonated beverages

Histo:	bacterial invasion of submucosa + subserosa
Organism:	hemolytic streptococcus, Clostridium welchii, Clostridium perfringens, E. coli, S. aureus, enterobacter, P. aeruginosa

• explosive onset of severe abdominal pain

• nausea, diarrhea, chills, fever, leukocytosis

• bloody foul-smelling emesis PATHOGNOMONIC vomiting of a necrotic cast of stomach (due to dissection along plane of muscularis mucosae)

CT:

• gastric wall thickening (DDx: emphysematous gastritis)

Plain radiographs:

• innumerable small gas bubbles silhouetting the stomach in a mottled fashion without positional change

• thickening of rugal folds

• portal venous gas

GI:

• cobblestone appearance of mucosa on upper GI

• intramural penetration of contrast material

Cx:	cicatricial stenosis (21%), sinus tract formation
Prognosis:	60 80% mortality
Rx:	broad-spectrum antibiotics + intravenous fluids; emergent surgery for acute perforation

Erosive Gastritis

• = HEMORRHAGIC GASTRITIS

Incidence:

0.5 10% of GI studies

Etiology (in 50% without causative factors):

• Peptic disease: emotional stress, alcohol, acid, corrosives, severe burns, anti-inflammatory agents (aspirin, steroids, phenylbutazone, indomethacin)

• Infection: herpes simplex virus, CMV, Candida

• Crohn disease: aphthoid ulcers identical in appearance to varioliform erosions

Histo:

epithelial defect not penetrating beyond muscularis mucosae

• 10 20% of all GI hemorrhages (usually without significant blood loss)

• vague dyspepsia, ulcerlike symptoms

Location:

antrum, rarely extending into fundus; aligned on surface of gastric rugal folds

• varioliform complete erosion (95%) = tiny fleck of barium surrounded by radiolucent halo ( target lesion ) <5 mm, usually multiple

• incomplete erosion (5%) = linear streaks/dots of barium without surrounding mound of edema/inflammation

• nodularity/scalloping of prominent antral folds

• contiguous duodenal disease may be present

• limited distensibility, poor peristalsis/atony, delayed gastric emptying

Phlegmonous Gastritis

Etiology:	septicemia, local abscess, postoperative stomach, complication of gastric ulcer/cancer
Organism:	Streptococcus
Path:	multiple gastric wall abscesses, which may communicate with lumen

• severe fulminating illness

• patient may vomit pus

Location:

usually limited to stomach not extending beyond pylorus; submucosa is the most severely affected gastric layer

• barium dissection into submucosa + serosa

Gastrointestinal stromal tumor

• = GIST = SPINDLE CELL/EPITHELOID TUMOR

Origin:

KIT-positive gut pacemaker cell = precursor of the interstitial cell of Cajal of myenteric plexus

• Most common mesenchymal neoplasm of GI tract

Incidence:	4500 6000 new cases per year (USA)
Age:	>50 years
Histo:	spindle cell (70 80%)/epithelioid (20 30%) morphology/mixture of both

Location:

• GI tract anywhere between esophagus and anus:

  • stomach (37 70%), small intestine (20 33%), duodenum (9%), anorectum (5 7%) > colon (4%) > esophagus (2%)

  • 75% of mesenchymal tumors in the esophagus are leiomyomas, 25% GIST

  • Stomach is the most common location of GIST = 2 3% of all gastric tumors

• peritoneum (4%), omentum; mesentery; retroperitoneum

Site:

muscularis propria (leiomyomas arise from muscularis mucosae)

P.838

• early satiety, indigestion, bloating, vague abdominal pain

• often not detected until late in their progression

• gastrointestinal bleeding (from mucosal ulceration)

• expresses transmembrane receptor tyrosine kinase encoded by KIT gene (CD117) in 95%; 70% of GISTs coexpress CD34

Associated with:	neurofibromatosis type 1
Spread:	(in 50% at presentation)

• adjacent organ invasion, ascites, omentum, peritoneum, liver metastasis

• Lymphadenopathy is NOT a feature!

• large hypervascular enhancing mass in prominent extraluminal location

• heterogeneous texture due to necrosis, hemorrhage, cystic degeneration

• ulceration + fistulization to GI lumen (common)

• tumor vessels visible within tumor

• displacement of adjacent organs + vessels

• @ Stomach

  • well-circumscribed mass up to 30 cm in size

  • features of submucosal mass:

    • lesion margin obtuse/at right angle with gastric wall (in profile)

    • smoothly circumscribed (en face)

  • smooth mucosal surface (common)

  • mucosal ulceration (in up to 60%)

  • polypoid intraluminal mass (in 14%

CT:

• extragastric extension into gastrohepatic/gastrosplenic ligament/lesser sac (in 86%)

• peripheral enhancement in 92% (corresponding to viable tumor)

• central areas of low attenuation (corresponding to hemorrhage, necrosis, cyst formation)

• cavity containing air/air-fluid level/oral contrast medium communicates with gastric lumen

• calcified in 3%

MR:

• solid tumor portion hypointense on T1WI + hyperintense on T2WI + enhancement

• tumoral hemorrhage varies from high to low signal intensity on T1WI + T2WI depending on age

DDx:

leiomyoma, leiomyosarcoma, schwannoma, neurofibroma, carcinoid

• @ Small intestine

• @ Anorectum

Cx:	bowel obstruction (rare)
Rx:	(1) surgery for localized primary (2) imatinib (= tyrosine kinase inhibitor) inhibits growth of GIST (paradoxical enlargement due to tumor hemorrhage/necrosis)

Giardiasis

• = overgrowth of commensal parasite Giardia lamblia

Organism:

• Giardia lamblia (flagellated protozoan); often harmless contaminant of duodenum + jejunum in motile form (= trophozoite) attached to mucosa by suction disk, nonmotile form (= cyst) shed in feces; capable of pathogenic behavior with invasion of gut wall

Incidence:	1.5 2% of population in United States, infests 4 16% of inhabitants of tropical countries, found in 3 20% of children in parts of southern USA
Predisposed:	altered immune mechanism (dysgammaglobulinemia, nodular lymphoid hyperplasia of ileum)
Histo:	blunted villi (may be misdiagnosed as celiac disease especially in children), cellular infiltrate of acute + chronic inflammation in lamina propria

• abdominal pain, weight loss, failure to thrive (especially in children)

• spectrum from asymptomatic to severe debilitating diarrhea, steatorrhea (related to number of organisms)

• reduced fat absorption (simulating celiac disease)

Location:

most pronounced in duodenum + jejunum

• thickened distorted mucosal folds in duodenum + jejunum (mucosal edema) with normal ileum

• marked spasm + irritability with rapid change in direction + configuration of folds

• hypersecretion with blurring + indistinctness of folds

• hyperperistalsis with rapid transit time

• segmentation of barium (from motility disturbance + excess intraluminal fluid)

• lymphoid hyperplasia (associated with immunoglobulin deficiency state)

Dx:	(1) Detection of Giardia lamblia cysts in formed feces or trophozoites in diarrheal stools (2) Trophozoites in duodenal aspirate/jejunal biopsy
DDx:	Strongyloides/hookworm infection
Rx:	quinacrine (Atabrine )

Glomus Tumor of Stomach

• Most common benign vascular gastric tumor

Histo:

dilated irregularly shaped thin-walled vessels (= modified capillaries) covered by nests/strands/sheets of glomus cells

• asymptomatic/upper GI bleeding

Location:

gastric antrum

• single smooth submucosal mass ulceration

• tiny flecks of calcification (occasionally)

• strong enhancement in early arterial phase

Glycogen Acanthosis

• = benign degenerative condition with accumulation of cellular glycogen within squamous epithelial lining of esophagus

Incidence:	in up to 15% of endoscoped patients
Etiology:	unknown
Age:	middle-aged/elderly individuals
Histo:	hyperplasia + hypertrophy of squamous mucosal cells secondary to increased glycogen; no malignant potential

• asymptomatic

• white oval mucosal plaques of 2 15 mm in diameter on otherwise normal appearing mucosa

Location:

middle (common)/upper esophagus, in random distribution

• multiple 1 3-mm rounded nodules/plaques

Dx:	biopsy
DDx:	candida esophagitis (lesions disappear under treatment in contrast to glycogen acanthosis), reflux esophagitis

P.839

Graft-Versus-Host Disease

• = T lymphocytes from donor bone marrow cause selected epithelial damage of recipient target organs

Bone marrow transplantation for treatment of:

• leukemia, lymphoma, aplastic anemia, immunologic deficit, metabolic disorders of hematopoietic system, some metastatic disease

Incidence:	30 70% of patients with allogeneic (= donor genetically different from host) transplant
Target organs:	GI tract (small bowel), skin, liver

• @ Skin

  • maculopapular rash on face, trunk, extremities

• @ Liver

  • elevation of hepatic enzymes liver failure

• @ GI tract

  • profuse secretory diarrhea

  • abdominal cramping, fever, nausea, vomiting

Path:

severe mucosal atrophy/destruction

• shaggy fold thickening

• ribbon bowel = small bowel fold effacement with tubular appearance (DDx: viral enteritis, ischemia, celiac disease, radiation, soybean allergy)

• loss of haustration, spasm, edema, ulceration, granular mucosal pattern of colon (simulating ulcerative colitis)

• small bowel cast = prolonged coating of abnormal bowel for hours to days

• circular collections of contrast material on cross section + parallel tracks on longitudinal section

• severely decreased transit time

CT:

• abnormally enhancing thin layer of mucosa diffusely involving small + large bowel

• fluid-filled distended poorly opacified bowel (oral contrast material not given!)

• barium (from previous contrast enema) may become incorporated into bowel wall

Cx:	infection with opportunistic organisms, eg, Candida albicans, herpes virus, invasive fungal organisms, CMV, Varicella-zoster virus, Epstein-Barr virus, hepatitis viruses, Rotavirus, Adenovirus, Coxsackie virus A and B, P. carinii, pneumococcus
Prognosis:	fatal in up to 15% (due to opportunistic infections)
Rx:	steroids + cyclosporine
DDx:	superinfection with enteroviruses

Helicobacter Pylori Infection

Organism:	worldwide gram-negative spiral-shaped bacillus [formerly Campylobacter pylori]
Prevalence:	increasing with age; >50% of Americans >60 years of age
Path:	surface epithelial damage + inflammation with mucosal infiltration by neutrophils, plasma cells, and lymphoid nodules
Location:	gastric antrum > proximal half of stomach
Site:	beneath mucus layer on surface epithelial cells

• asymptomatic (vast majority)

• dyspepsia, epigastric pain

• gastritis (75% prevalence of H. pylori):

  • thickened gastric folds

  • polypoid gastritis mimicking malignant tumor

  • enlarged areae gastricae

• gastric ulcer (60 80% prevalence of H. pylori)

• duodenal ulcer (90 100% prevalence of H. pylori)

Dx:	(1) Endoscopic brushings + biopsy (2) Breath test measuring urease activity after ingestion of carbon-14 labeled urea (3) Serologic test for IgG antibodies
Rx:	triple therapy (= bismuth + metronidazole + tetracycline/amoxicillin) results in 95% cure rate after 2 weeks of therapy

Hemangioma of Small Bowel

Incidence:	7 10% of all benign small bowel tumors
Increased incidence in:	Turner syndrome, tuberous sclerosis, Osler-Weber-Rendu disease

• symptomatic (80%):

  • acute intermittent severe bleeding (melena)

  • acute/chronic life-threatening anemia

  • intestinal obstruction, intussusception, perforation

Path:	submucosal soft infiltrative polypoid mass
Location:	jejunum (55%), ileum (42%), duodenum (2%)

• multiple sessile compressible intraluminal filling defects

• nodular segmental mucosal abnormality

• phleboliths in intestinal wall

CT:

• well-circumscribed lobulated mass of mixed attenuation supplied by large artery

Henoch-Sch nlein Purpura

• = most common systemic allergic hypersensitivity-related acute small-vessel vasculitis in children

Precipitated by:	bacterial/viral infection, allergies, insect sting, drugs (eg, penicillin, sulfonamides, aspirin), certain foods
Cause:	deposition of IgA-dominant immune complexes in venules, capillaries, and arterioles
Age:	children (peak age of 5, range 3 10 years) + adults >20 years (in up to 30%)

• most frequent manifestations:

  • purpuric skin rash on legs + extensor surfaces on arms

  • colicky abdominal pain + GI bleeding

  • microscopic hematuria + proteinuria in 50% (from proliferative glomerulonephritis with IgA deposits demonstrated by immunofluorescence)

• often begins as an upper respiratory tract infection

• arthralgias of large joints

• multifocal bowel wall thickening (due to intramural hemorrhage + edema)

Cx:	(1) Bowel infarct/perforation/irreducible intussusception (3 5%) (2) Renal insufficiency (10 20%), end-stage renal disease (5%)
Rx:	high doses of corticosteroids + azathioprine

Hernia

Prevalence:	10% of SBO; 2nd most common cause of small bowel obstruction!
Nomenclature:	according to anatomic site of its orifice

P.840

External Hernia

• = bowel extending outside the abdominal cavity

Incidence:

95% of all hernias

Location:

• @ Ventral

  • Postoperative hernia

  • Trocar site hernia

    Incidence:

    1 3.6%

    • often Richter type hernia

  • Umbilical hernia

    • see below

  • Paraumbilical hernia

    • large defect through linea alba from diastasis of rectus abdominis muscle at umbilicus

  • Epigastric/hypogastric hernia

    • in linea alba above/below umbilicus

  • Spigelian hernia

    Frequency:

    2% of anterior abdominal hernias

    • = acquired ventrolateral hernia through defect in aponeurosis between transverse and rectus muscle of abdomen at junction of semilunar + arcuate lines below umbilicus

    • hernia sac dissects laterally to rectus abdominis muscle through a fibrous groove (= semicircular/spigelian line)

    • hernia sac lies beneath an intact external oblique aponeurosis

• @ Diaphragm

  • Bochdalek hernia

  • Morgagni hernia

• @ Lumbar

  Location:

  defect in lumbar muscles below 12th rib + above iliac cest

  • Grynflett-Lesshaft (upper)

    Borders:

    internal oblique m. (anteriorly), 12th rib (superiorly), erector spinae m. (posteriorly)

  • Inferior lumbar triangle (Petit) (lower)

    Borders:

    external oblique m. (anteriorly), iliac crest (inferiorly), latissimus dorsi m. (posteriorly)

• @ Pelvic floor

  • Obturator foramen

    • hernia between pectineus + external obturator muscles

  • Sciatic notch

  • Perineal hernia (rare)

    • (a) anterior perineal hernia = defect of urogenital diaphragm anterior to superficial transverse perineal m. + lateral to bulbocavernosus m. + medial to ischiocavernosus m. (only in females)

    • (b) posterior perineal hernia = defect in levator ani m./between levator ani m. and coccygeus m. posterior to superficial transverse perineal m.

    • defecating proctography

• @ Groin

  • Inguinal hernia

    • Most common type of abdominal wall hernia, M>F

    • direct inguinal hernia

      • = defect in Hesselbach triangle (bounded by inguinal ligament inferiorly, inferior epigastric artery superolaterally, fused aponeuroses of internal oblique + transverse abdominal muscles medially)

      • medial to inferior epigastric vessels

      • hernia contains bowel, mesenteric fat, vessels

    • indirect inguinal hernia

      • Most common hernia in children due to failure of obliteration of processus vaginalis accompanying the testis

      • lateral to inferior epigastric vessels originating at deep inguinal ring

    • Littre hernia = inguinal hernia containing Meckel diverticulum

  • Femoral hernia

    • M<F

    • medial to femoral vein within femoral canal

    • posterior to inguinal ligament

    Cx:

    high probability of incarceration

  • Richter hernia = entrapment of antimesenteric border of bowel in hernia orifice, usually seen in older women with femoral hernias

    • no palpable mass = difficult to diagnose

    • partial obstruction with patent bowel lumen

Internal Hernia

• = herniation of bowel through a developmental/surgically created defect of the peritoneum, omentum, mesentery or through an adhesive band

Incidence:

5% of all hernias, responsible for <1% of mechanical small bowel obstruction

• Classification of internal hernias:

  • retroperitoneal: usually congenital containing a hernia sac

    • paraduodenal (ligament of Treitz)

    • foramen of Winslow

    • intersigmoid

    • pericecal/ileocolic

    • supravesical

  • anteperitoneal:

    • small group of hernias without a peritoneal sac

    • transmesenteric (transverse/sigmoid mesocolon)

    • transomental

    • pelvic (including broad ligament)

• intermittent nausea, abdominal pain, distension (made worse by eating + standing and relieved by fasting + assuming a recumbent position)

• signs of bowel obstruction (only during symptomatic period)

• mass effect with displacement of other abdominal organs

Cx:

volvulus

Paraduodenal Hernia (53%)

• = congenital defect in descending mesocolon

• frequently asymptomatic

P.841

• LEFT through fossa of Landzert (75%)

  Location:

  to the left of 4th portion of duodenum at duodenojejunal junction (paraduodenal fossa = confluent zone of descending mesocolon + transverse mesocolon + small bowel mesentery

  • cluster of dilated small-bowel loops between pancreas + stomach

  • displacement of gastric wall anteriorly

  • displacement of duodenojejunal flexure + transverse colon inferiorly

  • engorged crowded vessels at entrance of hernia sac

  • CT:

    • encapsulated bowel loop displacing the inferior mesenteric vein (= landmark of the right margin of the descending mesocolon) anterolaterally

• RIGHT through mesentericoparietal fossa of Waldeyer (25%)

  Predisposed:	nonrotation of small bowel
  Location:	behind the root of small bowel mesentery caudal to SMA and inferior to 3rd portion of duodenum on right side

  • CT:

    • encapsulated bowel loop displacing the right colic vein (= landmark of left margin of the ascending mesocolon) anteriorly

    • looping of small intestine behind SMA + SMV below transverse portion of duodenum

    • SMV located ventral + to left of SMA

    • absence of normal horizontal duodenum

Cx:

partial/complete obstruction of small intestine (in 50%)

Lesser Sac Hernia (<10%)

• through foramen of Winslow in retrogastric location

• Invaginated gut:

  • ileum > jejunum, cecum, appendix, ascending colon, Meckel diverticulum, gallbladder, greater omentum

• gas-containing bowel loops in center of upper abdomen

• distended small bowel loops occupying space between stomach + liver

Iatrogenic Hernia

• Transmesenteric Hernia

  Cause:

  fenestration of transverse mesocolon in construction of Roux-en-Y loop

  • cluster of small-bowel loops (70%)

  • clustered small bowel outside colon compressed against abdominal wall without overlying omental fat (85%)

  • central displacement of colon (92%)

  • displacement of mesenteric trunk (85%)

  • engorged mesenteric vessels (85%)

• Hernia through Broad Ligament (very rare)

  • after laceration/fenestration during surgery or during pregnancy

Hiatal Hernia

Associated with:

diverticulosis (25%), reflux esophagitis (25%), duodenal ulcer (20%), gallstones (18%)

Sliding Hiatal Hernia (99%)

• = AXIAL HERNIA = CONCENTRIC HERNIA

• = esophagogastric junction (= termination point of converging gastric folds) >1.5 cm above diaphragmatic hiatus (= pinched appearance of gastric folds) with portion of peritoneal sac forming part of wall of hernia

Etiology:	rupture of phrenicoesophageal membrane due to repetitive stretching with swallowing
Incidence:	increasing with age

• reducible in erect position

• epiphrenic bulge = entire vestibule + sleeve of stomach are intrathoracic

• distance between B ring (if visible) and hiatal margin >2 cm

• peristalsis ceases above hiatus (end of peristaltic wave delineates esophagogastric junction)

• tortuous esophagus having an eccentric junction with hernia

• numerous coarse thick gastric folds within suprahiatal pouch (>6 longitudinal folds)

• gastroesophageal reflux

• CT:

  • dehiscence of diaphragmatic crura >15 mm

  • pseudomass within/above esophageal hiatus

  • increase in fat surrounding distal esophagus (= herniation of omentum through phrenicoesophageal ligament)

DDx:

normal temporary cephalad motion of esophagogastric junction by 1 2 cm into chest due to contraction of longitudinal muscle during esophageal peristalsis

Paraesophageal Hernia (1%)

• = ROLLING HIATAL HERNIA = parahiatal HERNIA

• = portion of stomach superiorly displaced into thorax with esophagogastric junction remaining in subdiaphragmatic position

• cardia in normal position

• herniation of portion of stomach anterior to esophagus

• frequently nonreducible

• may be associated with gastric ulcer of lesser curvature at level of diaphragmatic hiatus

Totally Intrathoracic Stomach

• = defect in central tendon of diaphragm in combination with slight volvulus in transverse axis of stomach behind heart (organoaxial rotation)

• cardia may be intrathoracic (usually)/subdiaphragmatic

• great gastric curvature either on right/left side

Congenitally Short Esophagus

• (not true hernia, very rare)

• = gastric ectopy by lack of lengthening of esophagus

• nonreducible intrathoracic gastric segment (in erect/supine position)

• cylindrical/round intrathoracic segment with large sinuous folds

P.842




• short straight esophagus

• circular narrowing at gastroesophageal junction, frequently with ulcer

• gastroesophageal reflux

Umbilical Hernia

• = protrusion of abdominal contents/fat into anterior abdominal wall via umbilical ring

Prevalence:	4% of all hernias; M < F
Cause:	failed closure of umbilical ring, obesity, multiple pregnancies, intraabdominal masses, liver failure, increased intraabdominal pressure, weak abdominal wall

• may contain fat/small bowel/colon

Cx:	strangulation, incarceration
DDx:	paraumbilical, spigelian, epigastric, incisional hernia

Hirschsprung Disease

• = AGANGLIONOSIS OF THE COLON = AGANGLIONIC MEGACOLON

• = absence of parasympathetic ganglia in muscle (Meissner plexus) + submucosal layers (Auerbach plexus) secondary to an arrest of craniocaudal migration of neuroblasts along vagal trunks before 12th week leading to relaxation failure of the aganglionic segment

Incidence:	1:5,000 8,000 live births; 15 20% of all neonatal bowel obstructions; usually sporadic; familial in 4%
Age:	during first 6 weeks of life of a full-term infant (70 80%); M:F = 4 9:1; extremely rare in premature infants
Associated with:	trisomy 21 (in 2%)
Location:	at varying distances proximal to anus, usually rectosigmoid (in 80%)

(a) ultrashort segment (= internal sphincter)	(very rare)
(b) short segment disease	(80%)
(c) long segment disease	(15%)
(d) total colonic aganglionosis	(5%)
(e) skip aganglionosis = sparing of rectum	(very rare)

• failure to pass meconium within first 48 hours of life

• intermittent constipation + paradoxical diarrhea (25%)

• bilious vomiting, abdominal distention

• rectal manometry with absence of spike activity

• generalized gaseous distention of bowel loops

• BE:

  • short patent colon usually of normal caliber

  • inverted cone shape at transition between abnormal

    • + normal bowel (MOST CHARACTERISTIC):

    • transition zone = aganglionic segment appearing normal in size (seen in 50% during 1st week of life)

    • dilatation of large + small bowel aborally from transition zone

  • normal-appearing rectum in 33%

  • marked retention of barium on delayed postevacuation films after 12 24 hours

  • 10 15-cm segment of persistent corrugated/convoluted rectum (= abnormal uncoordinated contractions of the aganglionic portion of colon) in 31% (DDx: colitis, milk allergy, normal intermittent spasm of rectum)

  N.B.:

  avoid digital exam/cleansing enema prior to radiographic studies!

• OB-US:

  • dilated small bowel/dilated colon

Cx:	Necrotizing enterocolitis Cecal perforation (secondary to stasis, distension, ischemia) Obstructive uropathy
Dx:	suction mucosal biopsy of rectum (increased acetylcholinesterase activity)
Rx:	Swenson pull-through procedure Duhamel operation Soave procedure

Hyperplastic Polyp of Colon

• = intestinal metaplasia consisting of mucous glands lined by a single layer of columnar epithelium; NO malignant potential

Path:	infolding of epithelium into the glandular lumen
Location:	rectosigmoid

• smooth rounded sessile elevation

• usually <5 mm in diameter

Hypertrophic Pyloric Stenosis

• = idiopathic hypertrophy and hyperplasia of circular muscle fibers of pylorus with proximal extension into gastric antrum

Incidence:	3:1,000; M:F = 4 5:1
Etiology:	inherited as a dominant polygenic trait; increased incidence in firstborn boys; acquired rather than congenital condition

Hypertrophic Pyloric Stenosis

Infantile Form of Hypertrophic Pyloric Stenosis

Age:

manifestation between 2 8 weeks of life

• nonbilious projectile vomiting (sour formula/clear gastric contents) with progression over a period of several weeks after birth (15 20%)

• positive family history

• palpable olive-shaped mass (80% sensitive in experienced hands, up to 14% false positive)

• nasogastric aspirate >10 mL (92% sensitive, 86% specific)

• UGI (95% sensitivity):

  Precautions:

  1. empty stomach via nasogastric tube before study
  2. remove contrast at end of study

  • elongation + narrowing of pyloric canal (2 4 cm in length):

    • double/triple track sign = crowding of mucosal folds in pyloric channel

    • string sign = passing of small barium streak through pyloric channel

    P.843

    
    

    • Twining recess = diamond sign = transient triangular tentlike cleft/niche in midportion of pyloric canal with apex pointing inferiorly secondary to mucosal bulging between two separated hypertrophied muscle bundles on the greater curvature side within pyloric channel

  • abnormal configuration of antrum:

    • pyloric teat = outpouching along lesser curvature due to disruption of antral peristalsis

    • antral beaking = mass impression upon antrum with streak of barium pointing toward pyloric channel

    • Kirklin sign = mushroom sign = indentation of base of bulb (in 50%)

  • gastric distension with fluid

  • active gastric hyperperistalsis:

    • caterpillar sign = gastric hyperperistaltic waves

• US:

  • target sign = hypoechoic ring of hypertrophied pyloric muscle around echogenic mucosa centrally on cross-section

  • elongated pylorus with thickened muscle:

    • pyloric muscle wall thickness 3 mm

    • pyloric volume >1.4 cm³ (= 1/4 [maximum pyloric diameter]² pyloric length); most criteria independent of contracted or relaxed state (33% false negative)

    • pyloric length (mm) + 3.64 muscle thickness (mm) > 25

    • pyloric transverse diameter 13 mm with pyloric channel closed

    • elongated pyloric canal 17 mm in length

  • cervix sign = indentation of muscle mass on fluid-filled antrum on longitudinal section

  • antral nipple sign = redundant pyloric channel mucosa protruding into gastric antrum

  • exaggerated peristaltic waves

  • delayed gastric emptying of fluid into duodenum

  Cx:

  hypochloremic metabolic alkalosis

• DDx:

  • infantile pylorospasm

    • muscle thickness between 1.5 and 2 mm

    • variable caliber of antral narrowing

    • antral peristalsis

    • delayed gastric emptying

    • elongation of pylorus

    Prognosis:	resolves in several days/ early stage of evolving pyloric stenosis
    Rx:	effective with metoclopramide/bentyl

  • Gastritis/milk allergy

    • circumferential/eccentric thickening of antral mucosa >2 3 mm

  • Duodenal obstruction from midgut volvulus

    • distended descending duodenum

    • reversal of SMA and SMV relationship

    • whirlpool sign = twisting of small bowel mesentery

  • Gastric diaphragm

Adult Form of Hypertrophic Pyloric Stenosis

Cause:

secondary to mild infantile form

• acute obstructive symptoms uncommon

• nausea, intermittent vomiting

• postprandial distress, heartburn

• Associated with:

  • peptic ulcer disease (in 50 74%) (prolonged gastrin production secondary to stasis of food)

  • chronic gastritis (54%)

• persistent elongation (2 4 cm) + concentric narrowing of pyloric channel

• parallel + preserved mucosal folds

• antispasmodics show no effect on narrowing

• proximal benign ulcer (74%), usually near incisura

Focal Pyloric hypertrophy

• = TORUS HYPERPLASIA

• = localized muscle hypertrophy on the lesser curvature

• = milder atypical form of HPS

• flattening of distal lesser curvature

Imperforate Anus

Prevalence:

1:5,000 live births

• LOW ANOMALY (55%)

  • = bowel has passed through levator sling

  • fistula to perineum/vulva

  Rx:

  readily reparable

• INTERMEDIATE DEFECT (least common)

  • = bowel ends within levator muscle as a result of abnormality in posterior migration of rectum

  • fistula opening low in vagina/vestibule

  Rx:

  2-/3-stage operation

• HIGH ANOMALY

  • = bowel ends above levator sling; M > F

  • fistulous connection to perineum/vagina/posterior urethra (air in bladder in males; air in vagina in females)

  Cx:	associated malformations more common + more severe
  Rx:	multiple surgical procedures

• distance between rectal air and skin will not accurately outline the extent of atretic rectum and anus (varying length during crying with increase in abdominal pressure + contraction of levator ani muscle)

• US:

  • 15 mm distance between anal dimple + distal rectal pouch on transperineal images indicates low lesion

• OB-US (earliest detection by 20 29 weeks GA):

  • absent/low disaccharidase level in amniotic fluid

  • dilated colon in lower pelvis with U-/S-shaped configuration intraluminal calcifications

  • normal amniotic fluid (unless also TE fistula)

  • absence of anal characteristics (= hypoechoic circular rim with central echogenic stripe)

Infectious Colitis

Cause:

• bacterium: Shigella, Salmonella, Yersinia, Campylobacter, Staphylococcus, Chlamydia trachomatis, amebiasis, tuberculosis

• fungus: histoplasmosis, mucormycosis, actinomycosis

• virus: herpesvirus, CMV, rotavirus

Location:

• diffuse involvement = CMV, E. coli

• limited to right colon = Shigella, Salmonella

P.844




• descending + sigmoid colon = schistosomiasis

• rectosigmoid = gonorrhea, herpesvirus, C. trachomatis (lymphogranuloma venereum)

CT:

• wall thickening + low attenuation

• homogeneous wall enhancement

• multiple air-fluid levels

• inflammation of pericolic fat

• ascites

Dx:

clinical

Intestinal Lymphangiectasia

• CONGENITAL LYMPHANGIECTASIA

  • = PRIMARY PROTEIN-LOSING ENTEROPATHY

  • = generalized congenital malformation of lymphatic system with atresia of the thoracic duct + gross dilatation of small bowel lymphatics; usually sporadic; may be inherited

  Age:

  presentation before 30 years

  • asymmetric generalized lymphedema (due to protein-losing enteropathy with hypoproteinemia)

  • chylous pleural effusions (45%)

  • diarrhea (60%), steatorrhea (20%)

  • vomiting (15%)

  • abdominal pain (15%) + distension

  • decreased albumin + globulin

  • lymphocytopenia (90%)

  • decreased serum fibrinogen, transferrin, ceruloplasmin

• ACQUIRED LYMPHANGIECTASIA

  Causes leading to dilatation of intestinal lymphatics:

  • Mesenteric adenitis

  • Retroperitoneal fibrosis

  • Diffuse small bowel lymphoma

  • Pancreatitis

  • Pericardial effusion with obstruction of thoracic duct

  • peripheral edema/anasarca (KEY SYMPTOM)

  • chylous + serous effusion

  • diarrhea, vomiting, abdominal pain, malabsorption, steatorrhea

  • hypoproteinemia secondary to protein loss into intestinal lumen

Path:

dilatation of lymph vessels in mucosa + submucosa + abundance of foamy fat-staining macrophages (negative for PAS)

• diffuse symmetric marked enlargement of folds in jejunum

  • + ileum (due to dilated intestinal lymphatics

  • + hypoproteinemic edema)

• slight separation + rigidity of folds

• dilution of barium column (considerable increase in intestinal secretions from malabsorption)

• no/mild dilatation of bowel

• Lymphangiogram (not always diagnostic):

  • hypoplasia of lower extremity lymphatics

  • occlusion of thoracic duct/large tortuous thoracic duct

  • obstruction of cisterna chyli with backflow into mesenteric + intestinal lymphatics

  • hypoplastic lymph nodes

Dx:	small bowel biopsy (dilated lymphatics in lamina propria + vascular core)
Rx:	low-fat diet with medium-chain triglycerides (direct absorption into portal venous system)
DDx:	Whipple disease (more segmentation + fragmentation, wild folds) Amyloidosis (edema + secretions usually absent) Hypoalbuminemia (less pronounced symmetric thickening of folds, less prominent secretions)

Intestinal Pseudoobstruction

Acute Colonic Pseudoobstruction

• = Ogilvie syndrome

  • [Sir William Heanage Ogilvie (1887 1971), English surgeon at Guy's Hospital, London]

• = rare clinical disorder with signs & symptoms & radiographic appearance of an acute large bowel obstruction but without mechanical obstruction

Pathogenesis:	imbalance in autonomic nervous system (sympathetic overactivity + parasympathetic suppression) after recent significant medical illness/surgical procedure
Cause:	retroperitoneal trauma, especially fracture (11 52%), pelvic/abdominal/cardiothoracic surgery (20%), infection (10%), cardiac disease [MI, CHF] (10%)

• In 50% associated with:

  • metabolic imbalance (hypokalemia, hypocalcemia, hypomagnesemia), drugs (narcotic analgesics, antidepressants, antipsychotic, calcium channel blockers, narcoleptics)

Age:

>60 years/younger patient with spinal disorder; M > F

• abdominal pain (80%), abdominal distension

• nausea & vomiting (80%)

• obstipation (40%), diarrhea

• fever (37%)

• bowel sounds present

• massively dilated colon, especially cecum + right hemicolon (occasionally extending to rectum)

• normal haustral markings

• colon cut-off sign (= lack of gas in distal colon)

• small bowel air-fluid levels

• absence of obstructive lesion on enema

Cx:	cecal perforation
Prognosis:	15 45% mortality
Rx:	nasogastric + rectal suctioning; neostigmine; colonic decompression (if cecum exceeds 10 cm)
DDx:	toxic megacolon, mechanical obstruction

Chronic Intestinal Pseudoobstruction Syndrome

• = nonpropulsive intestine characterized by impaired response to intestinal dilatation without definable cause; autosomal dominant

• Cause:

  • reduced density of interstitial cells of Cajal in colon (= intestinal pacemaker cells)

  • neuropathic disorder: amyloidosis, diabetes, multiple sclerosis, brainstem tumor, stroke, spinal cord injury, Parkinsonism, paraneoplastic syndromes (antineuronal nuclear antibodies)

  • myopathy: scleroderma

  P.845

  
  

  • Medication: anticholinergic antidepressant, calcium channel blocker, alpha-2 adrenergic agonists

Age:

neonatal period/delayed for months + years, M:F = 1:1

• recurrent attacks of nausea & vomiting (83%)

• abdominal pain (74%)

• abdominal distension (57%)

• constipation (36%), diarrhea (29%)

• persistently decreased peristalsis

• esophageal dilation + hypoperistalsis (lower third)

• excessive duodenal dilation (DDx: megaduodenum, superior mesenteric artery syndrome)

• mild to marked gaseous distension of proximal small bowel

• ligament of Treitz may be placed lower than usual

• delayed transit of barium through affected segments

• disordered motor activity (fluoroscopy)

• small bowel air-fluid levels + distension

• disturbed intestinal transit

Intraluminal Duodenal Diverticulum

• = congenital lesion secondary to elongation of an incomplete duodenal diaphragm

Age at presentation:

in young adult

• easy satiety

• vomiting

• upper abdominal cramping pain

Location:

2nd 3rd portion of duodenum

• barium-filled sac within duodenal lumen (pathognomonic picture) = windsock, comma, teardrop appearance

• anchored to the lateral wall of the duodenum

• halo sign = duodenal mucosa covers outer + inner wall of diverticulum

Intramural Esophageal Rupture

• = DISSECTING INTRAMURAL HEMATOMA

• = mucosal tear with dissecting hemorrhage into submucosa and involvement of venous plexus

• hematemesis

• intramural hematoma simulates retained solid material within lumen

• mucosal stripe sign = dissected mucosa floating within lumen

Anatomy of Intussusception

Intussusception

• = telescope-like invagination or prolapse of a segment of intestinal tract (= intussusceptum = donor loop) into the lumen of the adjacent intestine (= intussuscipiens = receiving loop)

• The intussuscipiens contains the folded intussusceptum with entering limb + returning limb + their mesentery

• IN CHILDREN (94%)

  Incidence:

  2 4:1,000 live births; most common abdominal emergency of early childhood

  • Leading cause of acquired bowel obstruction in childhood!

  • Etiology:

    • idiopathic (over 95%): mucosal edema + lymphoid hyperplasia following viral gastroenteritis; predominantly at ileocecal valve

    • lead point (5%):

      • infants <3 months: Meckel diverticulum (most common), duplication cyst

      • children >3 years of age: Burkitt lymphoma, polyp in Peutz-Jeghers syndrome, polypoid hemangioma, enterogenous cyst, ectopic pancreas, suture granuloma, periappendicitis, Henoch-Sch nlein purpura, coagulopathy, inspissated meconium

  mnemonic:

  H DIMPL

  • Henoch-Sch nlein purpura

  • Duplication

  • Idiopathic

  • Meckel diverticulum

  • Polyp

  • Lymphosarcoma

  Age:

  peak incidence between 6 months and 2 years; 3 9 months (40%); <1 year (50%); <2 years (75%); >3 years (<10%); M:F = 2:1

  • abrupt onset of violent crampy pain (94%)

  • vomiting (91%)

  • red currant jelly stools/hematochezia (66%) usually only after >48 hours duration

  • palpable abdominal mass (59%)

  • diarrhea

  • restlessness, pallor, fever

  Types:	ileocolic (75 95%) > ileoileocolic (9%) > ileoileal (4%) > colocolic
  Location:	transverse colon + hepatic flexure + ascending colon (90%)
  Cx:	vascular compromise secondary to incorporation of mesentery (hemorrhage, infarction, acute inflammation)

• IN ADULTS (6%)

  Incidence:

  accounts for <16% of all bowel obstructions; 0.05% of CT exams

  P.846

  
  

  • Etiology:

    • specific cause (80%):

      • Tumor: benign (1/3), malignant (1/5)

      • Postsurgical changes (1/3): adhesions adjacent to sutures/submucosal bowel edema/discoordinated motility

      • Invaginated (= inverted) Meckel diverticulum

      • Prolapsed gastric mucosa

      • Aberrant pancreas

      • Foreign body, feeding tube

      • Chronic ulcer (TB, typhoid)

      • Prior gastroenteritis

      • Gastroenterostomy, trauma

      spontaneous without anatomic lead point:

      • celiac disease, scleroderma, Whipple disease, fasting, anxiety, agonal state

    • idiopathic (20%)

  • recurrent episodes of colicky pain, nausea, vomiting

  • abdominal tenderness, distention

  • change in bowel habits

  • palpable mass (in up to 50%)

  • bloody stool (in majority)

  Location:	ileoileal (40%) > ileocolic (15%)
  small bowel (55%):	benign neoplasm (40%), malignant neoplasm (17%), nonneoplastic (43%)
  colon (45%):	malignant neoplasm (48%), benign neoplasm (21%), nonneoplastic (31%)
  Prognosis:	self-limiting if intussusception <3.5 cm in length

Plain film (40 90% accuracy):

• no abnormality in 25%

• abdominal soft-tissue mass (50 60%), usually in RUQ:

  • target sign = soft-tissue mass with concentric circular areas of lucency (due to mesenteric fat of intussusceptum)

  • meniscus sign = crescent of gas within colonic lumen that outlines the apex of the intussusceptum

  • loss of inferior hepatic margin

• little air in small intestine/gasless abdomen

• air in displaced appendix

• small bowel obstruction (25%)

Antegrade barium study:

• coiled spring appearance

• beaklike abrupt narrowing of barium column demonstrating a central channel

Diagnostic enema:

Indication:	unusual age of child (<2 months, >4 years), high fever, peritoneal signs
Contraindication:	free air

• meniscus sign = convex intracolic mass = rounded apex of intussusceptum protrudes into contrast column

• coiled spring sign = edematous mucosal folds of returning limb of intussusceptum outlined by contrast material within lumen of colon

US (98 100% sensitive, 88 100% specific):

• readily detectable mass over 5.0 2.5 cm

• crescent-in-doughnut/target/bull's eye sign (on transverse scan) = concentric rings of alternating hypoechoic + hyperechoic layers (= intussuscipiens) with central hyperechoic portion (= mesentery of intussusceptum)

• pseudokidney/sandwich/hay fork sign (on longitudinal scan) = hypoechoic layers on each side of echogenic center of mesenteric fat

• peritoneal fluid trapped inside intussusception in <15% (associated with irreducibility + ischemia)

• echogenic mesentery contains lymph nodes + cecoappendiceal complex close to base of intussusception

• color Doppler demonstrates mesenteric vessels dragged between entering + returning wall of intussusceptum

  • Absence of blood flow within the intussusceptum suggests bowel necrosis (47%)!

  • Presence of blood flow within the intussusceptum is a good predictor of reducibility!

CT:

• multiple concentric rings = 3 concentric cylinders (central cylinder = canal + wall of intussusceptum; middle cylinder = crescent of mesenteric fat; outer cylinder = returning intussusceptum + intussuscipiens)

• proximal obstruction

Hydrostatic/Pneumatic Reduction

<1% mortality if reduction occurs <24 hours after onset!

Overall success rate:	70 85%
Contraindications:	pneumoperitoneum, peritonitis, hypovolemic shock Obtain abdominal radiograph to document absence of perforation before reduction!

Technique:

• Sedation (debated) with morphine sulfate (0.2 mg/kg IM)/fentanyl citrate IV (straining increases intraluminal pressure of distended colon)

• Anal seal with 24-F Foley catheter + balloon inflation to size equal to interpediculate distance of L5; balloon pulled down to levator sling; taped to buttocks; both buttocks firmly taped together

• 60% wt/vol barium sulfate with container between 24 36 inches above level of anus

• Maximally 3 attempts for 3 minutes each

• Manual manipulation increases colonic pressure

• Reduction should be accomplished within 10 minutes

• Extensive reflux into small bowel desirable to exclude residual ileoileal intussusception

• rule of 3s :

  • 3.5 feet (105 cm) above table (= 120 mm Hg)

  • 3 attempts

  • 3 minutes between attempts (delay allows venous congestion + edema to subside)

  • Alternative medium:

    • 1:4 Gastrografin -water solution raised to a height of 5 feet (150 cm)

    • air: delivers higher intracolonic pressures, faster, less fluoroscopic time, smaller tears, less contamination of peritoneal cavity

    • Ultrasound-guided saline enema: no limit to procedure time, low perforation rate

P.847

Cx:	perforation (0.4 3%; colonic bursting pressure ~200 mm Hg); reduction of nonviable bowel; incomplete reduction; missed lead point
Prognosis:	3.5 10% rate of recurrence

Ischemic Colitis

• = nonocclusive ischemic disease (major mesenteric vessels usually patent) characterized by acute onset + rapid clinical and radiographic evolutionary changes

Etiology:

decrease in blood flow to 20% of normal flow associated with small vessel disease (hypoxia) + reperfusion injury when blood flow is reestablished; injury more severe if terminal vascular branches obstructed rather than proximal mesenteric arcades

Path:

• mucosal congestion, patchy necrosis, ulcerations + submucosal edema and hemorrhage (mucosa + submucosa most sensitive to ischemia)

  • Early mucosal injury is reversible

• injury of muscularis propria (after severe + prolonged ischemia) can lead to transmural necrosis

  • Fibrotic stricture, perforation, severe sepsis

Precipitating factors:

• bowel obstruction: volvulus, carcinoma (proximal dilatation with increased intraluminal pressure and reduced blood flow)

• thrombosis: cardiovascular disease, myocardial infarction, digitalis treatment, arrhythmia, oral contraceptives, hypotensive episode, collagen vascular disease, sickle cell disease, hemolytic-uremic syndrome

• trauma: aortoiliac reconstruction (2%) with ligation of IMA, cardiac surgery

• idiopathic/spontaneous: mainly in elderly

mnemonic:

VINTS

• Vasculitis

• Incarceration (hernia, volvulus)

• Nonocclusive ischemia (shock, CHF)

• Thrombosis (atherosclerosis, emboli, polycythemia vera, hyperviscosity)

• Spontaneous

Age:

usually >50 years; M = F

• abrupt onset of lower abdominal pain + rectal bleeding

• abdominal tenderness, diarrhea

• lack of sepsis

• negative stool cultures

Location:

segmental involvement of any part of colon; entire colon (11%); right colon (30%); transverse colon (9%); left colon (46 90%); sigmoid colon (4%); rectum spared;
most commonly affected segments:

1. Griffith point (80%) = junction between distribution of superior + inferior mesenteric arteries at the splenic flexure
2. point of Sudeck = anastomotic plexus between inferior mesenteric artery + hypogastric vascular supply at rectosigmoid junction

Mean length of segmental involvement: 19 cm

Plain film (usually normal):

• segmental thumbprinting = marginal indentations on mesenteric side (rare finding on plain film)

BE (in 90% abnormal):

• Single contrast may efface thumbprinting, but double contrast overall is more sensitive!

• thumbprinting (75%) due to submucosal hemorrhage + edema

• transverse ridging = markedly enlarged mucosal folds (spasm), some wall pliability is preserved

• serrated mucosa = inflammatory edema + superficial longitudinal/circumferential ulceration

• deep penetrating ulcers (late)

CT (detection rate of 26 39%):

• symmetric/lobulated segmental thickening of colonic wall between 2 and 20 (mean 8) mm:

  • shaggy configuration + alternate layers of high and low attenuation (double halo sign) + marked pericolic streakiness of edema (wet appearance in 61%)

  • sharply defined homogeneously enhancing wall + mild mural thickening (dry appearance in 33%)

• loss of haustral markings

• irregular narrowed atonic lumen (= thumbprinting)

• curvilinear collection of intramural gas (6%) suggests bowel infarction

• portal + mesenteric venous air

• blood clot in SMA/SMV

US:

• absence/barely visible color flow

• absence of arterial signals

• nonstratified (= indistinct layers) thickened bowel wall >3 mm

Angio (findings similar to inflammatory disease):

• normal/slightly attenuated arterial supply

• mild acceleration of arteriovenous transit time

• small tortuous ectatic draining veins

Prognosis:

• Transient ischemia = complete resolution within 1 3 months (76%)

• Stricturing ischemia = incomplete delayed healing

  • narrowed foldless segment of several cm in length with smooth tapering margins

• Gangrene with necrosis + perforation (extremely uncommon)

• Mortality rate of 11 36%

DDx:

1. dry appearance: ulcerative/granulomatous colitis
2. wet appearance: pseudomembranous colitis, CMV colitis

Jejunal Atresia

• Air may be injected through nasogastric tube

• BE to exclude 2nd and 3rd areas of atresia

Cause:	intrauterine ischemic injury to developing gut
Age:	majority presenting during 1st day of life
In 25% associated with:	malrotation, volvulus, gastroschisis, omphalocele

• bilious vomiting, abdominal distension, failure to pass meconium

Plain film:

N.B.:

difficult to tell colon from small bowel in neonate

• 2 3 dilated bowel loops

• absence of gas in lower portion of abdomen

P.848

BE:

Purpose:

to exclude large-bowel causes of obstruction, show anatomical size of colon, demonstrate meconium ileus

• microcolon/small colon/colon of normal caliber (due to sufficient intestinal secretions in remaining small bowel)

Cx:

meconium peritonitis (5%)

Jejunoileal Diverticular Disease

• = JEJUNAL DIVERTICULOSIS

• = rarest form of gastrointestinal diverticular disease

Cause:	disordered contractions of smooth muscle results in increased intraluminal pressure and mucosal herniation (= pulsion diverticula = false diverticula)
Incidence:	0.5 1.1 2.3% on UGI; 0.3 4.5% of autopsy series; M > F
Age:	6th 7th decades
Location:	80% in jejunum, 15% in ileum (usually solitary), 5% in jejunum + ileum
Site:	on mesenteric border near entrance of vasa recti intermittent upper abdominal pain, flatulence, episodes of diarrhea (30%)
Size:	a few millimeters to >10 cm

• Plain film:

  • air-fluid levels in multiple diverticula

  • slight dilatation of intestinal loops in area of diverticula

• BE:

  • may not fill (narrow neck/stagnant secretions)

  • trapped barium on delayed film after 24 hours

• Cx:

  • Blind loop syndrome with bacterial overgrowth

    • steatorrhea, diarrhea, malabsorption, weight loss

    • megaloblastic anemia (overgrowth of coliform bacteria leads to deconjugation of bile acids + intraluminal metabolism of vitamin B12)

  • Free perforation = leading cause of pneumo-peritoneum without peritonitis (21 40% mortality)

  • Hemorrhage (few cases)

  • Diverticulitis

  • Intestinal obstruction (enterolith ileus)

Juvenile Polyposis

• = rare autosomal dominant disease with variable penetrance characterized by development of multiple (>5) juvenile polyps in GI tract

• Most common familial/nonfamilial colonic polyp in children (75%)!

• Categories:

  • Juvenile polyposis of infancy

    Age:

    4 6 years (range 1 10 years); M:F = 3:2

    • protein-losing enteropathy, diarrhea, hemorrhage

    • rectal prolapse

    • intussusception

  • Colonic & generalized juvenile polyposis

    Age:

    in 85% manifested by 20 years of age

    • prolapse of polyp/rectum

    • rectal bleeding, anemia

Path:	hamartomatous polyps; adenomas may coexist
Histo:	little/no smooth muscle; hyperplasia of mucous glands; retention cysts develop with obstruction of gland orifices (multiple mucin-filled spaces); edematous inflamed expanded lamina propria
DDx:	familial adenomatous polyposis, Peutz-Jeghers syndrome

• rectal bleeding (95%) most commonly as intermittent bright red hematochezia

• anemia, pain

• diarrhea, constipation

• abdominal pain (from intussusception)

• rectal prolapse (rare)

Location:

rectosigmoid (80%); rare in small bowel + stomach; not in esophagus

• solitary polyp (75%); multiple polyps (1/3) of smooth round contour

• lesion of pinpoint size/up to several cm in diameter

• invariably on stalk of variable length

Dx:	Any number of polyps with family history Polyps throughout the GI tract >5 10 polyps in colon
Cx:	colorectal cancer by 35 years of age (in 15%)
DDx:	solitary juvenile polyps (<5 polyps, 1% prevalence in children)

Kaposi Sarcoma

• [Moritz Kaposi (1837 1902), dermatologist in Vienna, Austria]

• = multicentric malignant neoplasm originating from endothelial cells of lymphatic/blood vessels

Cause:	HIV regulatory protein (trans-activator target [TAT]) important for viral replication is thought to cause proliferation of Kaposi sarcoma cells
Incidence:	most common AIDS-related neoplasm (10 20 34%); in 51% of homosexual/bisexual men with AIDS; rare in hemophiliacs; M:F = 50:1
Histo:	proliferation of spindle cells with numerous extra-vasated RBCs located in clefts between stromal cells

• Types:

  • Classic Kaposi sarcoma

    • affecting men of Mediterranean origin in 7th decade

  • Central African Kaposi sarcoma

  • AIDS-related Kaposi sarcoma

• @ Skin (most frequent site)

  • multiple bluish red slightly elevated skin lesions

• @ Lymph nodes (2nd most frequent site):

  • abdominal + pelvic lymphadenopathy with high contrast-enhancement (secondary to vascularity)

  • Associated with high frequency of GI tract involvement

• @ GI tract (40 50%, 3rd most frequent site):

  • usually clinically silent

  • concurrent with/after cutaneous disease

  • GI tract is the only site of involvement in <5%!

  Location:

  anywhere within GI tract; often multifocal

  • thickened nodular folds

  • multiple submucosal nodules central umbilication

  • polypoidal mass

  • infiltrating linitis plastica lesion (rare)

• @ Liver (34% at autopsy)

  • infrequently contributes to morbidity + mortality

  P.849

  
  

  • multiple 5 12-mm nodules hyperechoic on US, hypoattenuating on NECT/CECT indistinguishable from multiple hemangiomas

  DDx:

  metastatic disease, fungal microabscesses, multiple areas of bacillary angiomatosis (= swollen venous lakes in liver)

• @ Lung (18 47% of patients with cutaneous sarcoma):

  • = late complication of AIDS

  Site:

  peribronchial + perivascular axial interstitium (91%); middle/lower lung zones (92%)

  • coarsening of bronchovascular bundles:

    • tram track opacities

    • peribronchial cuffing

    • septal lines (38 71%)

  • central perihilar coalescent consolidation air bronchograms in 45% (= confluent tumor)

  • small (50%)/large (28%) pulmonary nodules (= tumor proliferation extending into parenchyma)

  • pleural effusion (33 67%), chylothorax (rare)

  • moderate lymphadenopathy (16%)

• @ Lower extremities

  • lytic cortical lesion

  • subcutaneous nodules

Dx:

visualization + biopsy of mass with red-purple color

Ladd Bands

• = congenital peritoneal bands extending from cecum/hepatic flexure over anterior surface of 2nd/3rd portion of duodenum causing duodenal obstruction at its 2nd portion (even without volvulus)

Associated with:

malrotation

• oblique termination of duodenal contrast column

Leiomyoma

Location:	2/3 occur in stomach
Path:	arising from muscularis propria/submucosa/muscularis mucosae/smooth muscle of blood vessels within wall of viscus
Histo:	intersecting bands of muscle + fibrous tissue in a well-defined capsule difficult to differentiate from leiomyosarcoma
DDx:	fibroma, neurofibroma, hemangioma

Esophageal Leiomyomatosis

Age:	6 18 (mean of 11) years; M > F
Cause:	sporadic (50%) familial disease (20%): leiomyomas of uterus, vulva, tracheobronchial tree, small bowel, rectum Alport syndrome (30%) = nephritis, high-frequency sensorineural hearing loss, congenital cataract
Site:	distal third/half of esophagus extension into proximal stomach

• slowly progressive dysphagia over years

• smooth tapered narrowing of distal esophagus over an average length of 6 cm

• decreased/absent esophageal peristalsis

• smooth relatively symmetric defect at cardia (from thickened muscle bulging into gastric fundus)

• CT:

  • marked circumferential wall thickening of up to 4 cm from mass with relatively low soft-tissue attenuation

  DDx:

  1. Primary achalasia (shorter narrowed segment)
  2. Secondary achalasia (older individual, recent onset of dysphagia)
  3. Stricture from reflux esophagitis
  4. Idiopathic muscular hypertrophy of the esophagus (in late adulthood, corkscrew appearance of esophagus with nonperistaltic contractions, cardia rarely involved)

Leiomyoma of Esophagus

• Most common benign submucosal tumor of esophagus

Incidence:	1:1,119 (autopsy study); 50% of all benign esophageal tumors
Age:	young adults; 3% in children; M > F

• usually asymptomatic (due to slow growth)

• dysphagia, odynophagia, dyspepsia

• hematemesis if large (rare)

Site:

frequently lower + mid 1/3 of esophagus; intramural; multiple leiomyomas in 3 4%

• 2 15-cm large smooth well-defined intramural mass

  • causing eccentric thickening of wall + deformity of lumen

• may have coarse calcifications:

  • Leiomyoma is the only calcifying esophageal tumor!

• ulceration extremely uncommon

• CT:

  • uniform soft-tissue density

  • diffuse contrast enhancement

CAVE:

high percentage misdiagnosed as extrinsic lesion!

Leiomyoma of Small Bowel

Most common benign tumor of small bowel

Location:	duodenum (21%), jejunum (48%), ileum (31%); single in 97%
Site:	mainly serosal (50%), mainly intraluminal (20%), intramural (10%)
Size:	<5 cm (50%), 5 10 cm (25%), >10 cm (25%)

• small ulcer + large barium-filled cavity (central necrosis + communication with lumen)

• hypervascular

Leiomyoma of Stomach

• 2nd most common benign gastric tumor (after gastric polyp), most common of calcified benign tumors

Location:	pars media (39%), antrum (26%), pylorus (12%), fundus (12%), cardia (10%)
Site:	intraluminal submucosal (60%), exophytic subserosal (35%), combined intramural-extramural dumbbell type mass (5%) 90% of all submucosal tumors!

• average size of 4.5 cm

• ovoid mass with smooth margin + smooth surface (most frequently)

• forms right angle with gastric wall

• ulcerated in 50%

• pedunculated intraluminal tumor in submucosal growth (rare)

P.850




• iceberg phenomenon = large extraluminal component in subserosal growth

• calcifies in 4%

Cx:

1. Hemorrhage (acute/chronic)
2. Obstruction (tumor bulk/intussusception)
3. Infection
4. Fistulization/perforation
5. Malignant degeneration (benign:malignant = 3:1)

Leiomyosarcoma

Leiomyosarcoma of Small Bowel

Location:

duodenum (26%), jejunum (34%), ileum (40%)

• usually >6 cm in size

• nodular mass: intraluminal (10%), intraluminal pedunculated (5%), intramural (15%), chiefly extrinsic (66%)

• mucosa may be stretched + ulcerated (50%)

• may show central ulcer pit/fistula communicating with a large necrotic center

• intussusception

Leiomyosarcoma of Stomach

Incidence:	0.1 3% of all gastric malignancies
Age:	10 73 years; M > F
Histo:	pleomorphism, hypercellularity, mitotic figures, cystic degeneration, necrosis

• GI bleeding (from ulceration)

• obstruction

• Metastases:

  • hematogenous to liver, lung, peritoneum; rarely to bone + soft tissue

  • direct extension into omentum, retroperitoneum

  • lymph nodes (rare)

Location:	90% in fundus/body of stomach
Site:	anterior/posterior wall; endo-/exogastric

• average size of 12 cm

• intramural mass

• may be pedunculated

• large masses tend to be exogastric

• very frequently ulcerated

• CT:

  • lobulated irregular outline

  • heterogeneous exogastric mass with central zones of low density (necrosis with liquefaction)

  • air/positive contrast within tumor (= ulceration)

  • dystrophic calcifications

Carney Triad

Triad of	Gastric epithelioid leiomyosarcoma Functioning extraadrenal paraganglioma Pulmonary chondromas
Incidence:	24 patients reported; M:F = 1:11

Lipoma

• = benign submucosal tumor composed of mature adipose tissue

• Most common submucosal tumor in colon

Incidence:	in colon in 0.25% (autopsy); 2 3% of benign gastric tumors
Location:	colon (particularly cecum + ascending colon) > duodenum > ileum > stomach (gastric antrum) > jejunum > esophagus

• asymptomatic

• crampy pain, hemorrhage (rare)

• smooth, sharply outlined, round/ovoid globular mass of 1 3 cm in diameter

• short thick pedicle in 1/3 caused by repeated peristaltic activity (prone to intussuscept)

• marked radiolucency

• change in shape + size on compression due to softness:

  • squeeze sign = sausage-shaped mass on postevacuation radiographs

• CT:

  • well-circumscribed submucosal mass of uniform fat density

Cx:	Intussusception (rare) Ulceration (from pressure necrosis of overlying mucosa by large lipoma; rare)
Prognosis:	NO liposarcomatous degeneration

Lymphangioma

• = congenital malformation of lymphatic vessels

Path:	usually multiloculated large thin-walled cystic mass with chylous/serous/hemorrhagic fluid contents
Location:	mesentery; rarely affecting GI tract

• proximal bowel dilatation (in partial bowel obstruction)

• US:

  • multiseptated cystic mass with lobules

  • fluid anechoic/with internal echoes/sedimentation

• CT:

  • cystic mass with contents of water- to fat-density

• MR:

  • serous contents: hypointense on T1WI + hyperintense on T2WI

  • hemorrhage/fat: hyperintense on T1WI + T2WI

Rx:

surgery (difficult due to intimate attachment to bowel wall)

Lymphogranuloma Venereum

• = LGV = sexually transmitted disease caused by virus Chlamydia trachomatis producing a nonspecific granulomatous inflammatory response in infected mucosa (mononuclear cells + macrophages), perirectal lymphatic invasion

Location:

rectum, extension to sigmoid + descending colon M:F = 3.4:1

• narrowing + shortening + straightening of rectosigmoid

• widening of retrorectal space

• irregularity of mucosa + ulcerations

• paracolic abscess

• fistula to pericolic area, rectum, vagina (common)

Rx:

tetracyclines effective in acute phase before scarring has occurred

Lymphoid Hyperplasia

Incidence:	normal variant in 13% of BE examinations
Histo:	hyperplastic lymph follicles in lamina propria (Peyer patches), probably compensatory attempt for immunoglobulin deficiency

Etiology:

• Normal in child/young adult

• Self-limiting local/systemic inflammation/infection/allergy

P.851




• May be related to immunodeficiency/dysgammaglobulinemia with small bowel involvement

Age:	generally in children <2 years in adults invariably associated with late onset immunoglobulin deficiency (IgA, IgM)
Associated with:	splenomegaly, large tonsils, eczematous dermatitis, achlorhydria, pernicious anemia, acute pancreatitis, colonic carcinoma

At risk for:

• Good syndrome (10%)

  • = gastric carcinoma + benign thymoma + lymphoid hyperplasia

• Respiratory infections

• Giardia lamblia infection (90%)

• Functional thyroid abnormalities

Location:

primarily jejunum, may involve entire small bowel, ascending colon + hepatic flexure, seldom in sigmoid/rectum

• malabsorption (diarrhea + steatorrhea)

• low serum concentrations of IgA, IgG, IgM

• mucosa studded with innumerable 1 3-mm small uniform polypoid lesions

• lesions may be umbilicated (uncommon)

Lymphoma of Gastrointestinal Tract

Classification:

• PRIMARY LYMPHOMA OF BOWEL

  • localized

  • diffuse

  Predisposed:	Arabs + Middle Eastern Jews
  Associated with:	celiac disease

• SECONDARY INTESTINAL LYMPHOMA

  • as part of generalized systemic process

Incidence:	4 20% of all NHL; 10% of patients with abdominal lymphoma have bowel involvement
At risk:	long-standing celiac disease, AIDS, systemic lupus erythematosus, Crohn disease, history of chemotherapy
Median age:	60 years

Histo:

• B-cell lymphoma (most common)

• T-cell lymphoma (in celiac disease/peripheral T-cell lymphoma)

• Immunoproliferative small intestinal disease

  • (= Mediterranean/Middle Eastern lymphoma) in young patients of poor socioeconomic status

• Low-grade B-cell lymphoma (= low-grade mucosa-associated lymphoid tissue = MALT lymphoma)

  • 50 72% of all primary gastric lymphomas;

  Associated with:

  Helicobacter pylori gastritis in 90% (may regress completely after antibiotic therapy)

• Follicular lymphoma

• Burkitt lymphoma (in children)

• Mantle cell lymphoma

• Hodgkin disease (<15%)

May be associated with:

enlargement of extraabdominal lymph nodes, malabsorption

Radiographic types:

• Polypoid/nodular (47%)

  • enlarged nodular folds

• Ulcerative (42%)

  • ulcerative lesions, may be complicated by perforation

  • aneurysmal configuration

• Diffusely infiltrating (11%)

  • diffuse hoselike thickening of bowel wall

  • decreased/absent peristalsis

CT staging:

Stage I	tumor confined to bowel wall
Stage II	limited to local nodes
Stage III	widespread nodal disease
Stage IV	disseminated to bone marrow, liver, other organs

Location:

10 25% of NHL are extranodal; stomach (50%) > small bowel > colon > esophagus; multicentric in 10 50%

• enlargement of spleen

• bulky enlargement of regional lymph nodes

• @ Esophagus

  • least common site of GI involvement (in <1%)

• @ Stomach

  • 1 5% of all gastric malignancies; most common site of extranodal lymphoma (25%); most frequent site of involvement by NHL (50%); isolated primary gastric malignancy in 10%

  Location:	no predilection for any particular region of stomach
  Site:	arises in lymphoid tissue of lamina propria that forms secondary to chronic Helicobacter pylori gastritis (normally gastric mucosa has no lymphoid tissue!)
  Direct extension into:	pancreas, spleen, transverse colon, liver

  • pliant gastric wall

  • duodenum often affected when antrum involved

  • circumscribed mass with endogastric/exogastric (25%) growth

  • broad tortuous mucosal folds over large portions of stomach (diffuse form):

    • polypoid/nodular

  • large irregular ulcer

  • rarely luminal narrowing

  • CT:

    • diffuse involvement of entire stomach (50%), typically more than half of gastric circumference

    • segmental involvement (15%)

    • ulcerated mass (8%)

    • average wall thickness of 4 5 cm

    • luminal irregularity (66%)

    • hyperrugosity (58%)

  Prognosis:	55% 5-year survival rate after resection
  DDx:	gastric adenocarcinoma (wall thickening less pronounced, perigastric fat plane not likely preserved, luminal narrowing, rigid wall, smaller lymph nodes above the level of renal veins)

• @ Small bowel

  • 1/5 of all small bowel malignancies; most common malignant small bowel tumor; multiple sites of involvement in 1/5; most common cause of intussusception in children >6 years

  P.852

  
  

  Location:	ileum (51%), jejunum (47%), duodenum (2%)
  Site:	arising from lymphoid patches of Peyer

  Radiographic types:

  • Nodular pattern

    • cobblestone defects due to lymphomatous polyps

    • mucosal/submucosal nodules may ulcerate

    • may cause intussusception

    • sprue pattern

  • Single mass

    • intussusception

    • obstruction unusual (soft + pliable tumor

  • Infiltrating pattern

    • plaquelike thickening of wall >5 cm in length (80%)/>10 cm in length (20%) (DDx: Crohn disease)

    • ulceration (considerable excavation)

    • desmoplastic response

    • thickened valvulae with corrugated appearance

    • aneurysmal dilatation in up to 50% (secondary to destruction of autonomic nerve plexus + muscle/tumor necrosis)

    • obstruction unusual (soft + pliable tumor

  • Exophytic = endoexoenteric mass

    • large mass with only small intramural component

    • ulcer + fistulas + aneurysmatic dilatation

    DDx:

    adenocarcinoma, GIST

  • Mesenteric/retroperitoneal adenopathy

    • single/multiple extraluminal masses displacing bowel

    • ill-defined confluent mass engulfing + encasing multiple loops of adjacent bowel

    • sandwich configuration = mass surrounding mesenteric vessels that are separated by perivascular fat

    • conglomerate mantle of retroperitoneal + mesenteric mass

• @ Colon

  • Less commonly involved than stomach/small bowel; 1.5% of all abdominal lymphomas

  Location:

  cecum most commonly involved (85%)

  • single mass > diffuse infiltration > polypoid lesion

  • paradoxical dilatation

  • gross mural circumferential/focal soft-tissue thickening (average size of 5 cm)

  • slight enhancement

  • massive regional + distant mesenteric + retroperitoneal adenopathy

DDx:	frequently resembles inflammatory disease/polyposis
Prognosis:	71 82% 2-year survival rate in isolated bowel lymphoma 0% 2-year survival rate in stage IV disease with bowel involvement
Cx during chemotherapy:	perforation (9 40%), hemorrhage

Peripheral T-Cell Lymphoma

Incidence:	5 30% of all NHL
Age:	middle age + elderly
Histo:	mature T-cell phenotype
Location:	bone marrow, skin, lung, liver, GI tract (4 6%)
Site:	small intestine (64%, esp. duodenum + jejunum)

• malabsorption

• multifocal bowel involvement (50 72% compared with 10 25% in B-cell lymphoma)

• bowel perforation with pneumoperitoneum (41 50% compared with <30% in B-cell lymphoma)

• mild (<1 cm)/moderate (1 2 cm) gastric/bowel thickening

• polypoid mass (rare; common in B-cell lymphoma)

• thickened plaques, ulcers, strictures (compared with exophytic/annular masses in B-cell lymphoma)

• nonbulky lymphadenopathy (compared with bulky lymphadenopathy in B-cell lymphoma)

• hepatosplenomegaly

Malignant Melanoma

• = develops from melanocytes derived from neural crest cells, arising in preexisting benign nevi (in 20%)

Incidence:	1% of all cancers; increasing at 3.9% per year
Peak prevalence:	40 60 years of age
Risk factors:	dysplastic mole, atypical melanocytic hyperplasia, xeroderma pigmentosum, melanoma in first-degree relative, sun-sensitive phenotype, excessive sun exposure
Sites:	skin, mucous membranes, leptomeninges, eye

• areas of red/white/blue in addition to brown and black colors of benign nevi

• irregular borders with notching + striking protrusions

• @ Skin primary

  Clark staging:
  Level I	all tumor cells above basement membrane (in situ lesion)
  Level II	tumor extends to papillary dermis
  Level III	tumor extends to interface between papillary + reticular dermis
  Level IV	tumor extends between bundles of collagen of reticular dermis
  Level V	tumor invasion of subcutaneous tissue (in 87% metastatic)
  Breslow staging:
  thin	<0.75 mm depth of invasion
  intermediate	0.76 3.99 mm depth of invasion
  thick	>4 mm depth of invasion

  METASTASES:

  • latent period of 2 20 years after initial diagnosis (most commonly 2 5 years)

  Primary site:

  head + neck (79%), eye (77%), GU system (67%), GI tract (in up to 60%)

• @ Lymphadenopathy

  • in 23% with level II + IV

  • in 75% with level V

  • sentinel node biopsy:

    • intraoperative intradermal injection of dye

    • preoperative lymphoscintigraphy

• @ Bone (7 17%)

  Prevalence:

  30 40% at autopsy

  • often initial manifestation of recurrence

  • poor prognosis

  • predominantly osteolytic

  Location:

  axial skeleton (80%), ribs (38%)

P.853




• @ Lung (70% at autopsy)

  • most common site of relapse; respiratory failure most common cause of death

• @ Liver (17 23%; 58 66% at autopsy)

  • single/multiple lesions 0.5 15 cm in size

  • larger lesion often necrotic

  • may be partially calcified

• @ Spleen (1 5%; 33% at autopsy)

  • single/multiple lesions of variable size

  • solid/cystic

• @ GI tract + mesentery (4 8%)

  • abdominal pain, GI bleeding

  Location:

  small intestine (35 50%), colon (14 20%), stomach (7 20%)

  • multiple submucosal nodules bull's-eye/target appearance = central ulceration

  • irregular amorphous cavity (exoenteric growth)

  • intussusception (10 20%)

• @ Kidney (up to 35% at autopsy)

• @ Adrenal (11%, up to 50% at autopsy)

• @ Subcutis

• MR of melanotic melanoma:

  • hypo-/isointense on T1WI + T2WI + STIR images (most commonly)

  • hyperintense on T1WI + hypointense on T2WI (due to T1-shortening effect of the paramagnetic metals iron + copper bound to melanin)

DDx:	melanotic/amelanotic hemorrhagic tumor (hyperintense on T1WI + iso-/hyperintense on T2WI)
Prognosis:	30 40% eventually die from this tumor

Mallory-Weiss Syndrome

• = mucosal + submucosal tear with involvement of venous plexus

Pathophysiology:	violent projection of gastric contents against lower esophagus
Age:	30 60 years; M > F
Predisposed:	alcoholics

• history of repeated vomiting prior to hematemesis

• massive painless hematemesis

Location:

at/above/below (76%) esophagogastric junction

• longitudinal single tear in 77%, in 23% multiple tears

• extravasation of barium

• Angio:

  • bleeding site at gastric cardia

DDx:

peptic ulcer/ulcerative gastritis

Malrotation

• abnormal position of gut secondary to a narrow mesenteric attachment as a result of arrest in the embryologic development of gut rotation + fixation

• Embryology:

  • duodenojejunal + ileocolic segments of primitive digestive tube rotate by 270 in a counterclockwise direction about the omphalomesenteric vessels to cross beneath the vessels (future SMA + SMV); normally LUQ fixation at ligament of Treitz (an extension of the right crus of diaphragm) + fibrous tissue around celiac artery, located to left of L2) + RLQ fixation of cecum

  • Abnormal fixation of mesentery: shorter than usual, its upper point below the normal position of ligament of Treitz, its lower point superior + medial to normal cecal position

Associated with:

urinary pseudoobstruction, prune-belly syndrome, cloacal exstrophy

• symptoms of partial/complete proximal bowel obstruction:

  • vomiting (77% of neonates; in 39% within 1st week of life)

  • recurrent attacks of vomiting + distension (in older children)

• Barium meal & barium enema:

  Purpose:

  guess the location of abnormal peritoneal fixation from position of bowel!

  • clearly abnormal position of duodenum (81%):

    • duodenum + jejunum to the right of spine (30%)

    • corkscrew duodenum + jejunum (29%)

    • duodenojejunal junction low + in midline (22%)

  • unusual abnormal position of duodenum (16%):

    • duodenojejunal junction over right pedicle

    • duodenojejunal junction to left of spine but low

    • duodenal redundancy to right of spine

    • Z-shape configuration of duodenum + jejunum

  • small bowel on right + colon on left side of abdomen (in 0.2% incidental finding in adults)

  • abnormal position of duodenum + cecum (84%)

  • normal position of duodenum (3%)

  • normal position of cecum (in 5 20%)

    DDx:

    mobile cecum (15%)

• CT:

  • SMV positioned to left of SMA (80%)

  • aplastic/hypoplastic uncinate process of pancreas

Cx:

midintestinal/midgut volvulus, duodenal obstruction, Ladd bands, internal herniation

Nonrotation

• = midgut loop returns to peritoneal cavity without rotation resulting in weak peritoneal fixation

Frequency:

common

• generally asymptomatic: often incidental finding in older children + adults

• SMA to right of SMV

• large intestine on left + small intestine on right

Cx:

volvulus (as a result of local clockwise rotation) with whirl sign around SMA

Incomplete Rotation

• = failure of midgut loop to complete final 90 of rotation

• prearterial segment of midgut reenters abdomen first toward left side

• cecum just inferior to pylorus

Cx:

duodenal obstruction (peritoneal bands pass over duodenum)

Reversed Rotation

Frequency:

rare

• postarterial segment of midgut reenters abdomen first

• = cecum migrates first passing behind SMA toward right thus unwinding the normal counterclockwise rotation of the first stage with additional final 90 clockwise rotation

P.854




• duodenum anterior to SMA

• transverse colon behind duodenum + SMA

Cx:

obstruction of transverse colon by pressure from SMA

Malrotation

Mastocytosis

• = URTICARIA PIGMENTOSA

• = systemic disease with mast cell proliferation in skin and RES (lamina propria of small bowel; bone; lymph nodes; liver; spleen) associated with eosinophils + lymphocytes

Age:	<6 months old (in 50%)
Associated with:	myeloproliferative disorders, acute nonlymphatic leukemia, malignant lymphoma, mast cell leukemia

Categories:

I	indolent mastocytosis (most frequent)
II	mastocytosis associated with myeloproliferative/myelodysplastic hematologic disorder
III	aggressive/lymphadenopathic mastocytosis with eosinophilia
IV	mast cell leukemia (rare)

• diarrhea, malabsorption, steatorrhea, anorexia

• urticaria pigmentosa = cutaneous form (in 80 90%):

  • hyperpigmented skin lesions exhibiting wheal and flare phenomenon when disturbed

• abdominal pain, nausea, vomiting

• tachycardia, asthma, flushing, gastrointestinal upset, headache, pruritus (due to liberation of histamine/prostaglandin D₂)

  caused by:

  physical exertion, heat, certain foods, alcohol, nonsteroidal antiinflammatory drugs

• pancytopenia (chronic neutropenia)

• @ Skeletal involvement (70%)

  • bone and joint pain

  • osteoporosis (due to release of heparin + prostaglandin by mast cells activating osteoclasts)

  • scattered well-defined sclerotic foci with focal/diffuse involvement (due to release of histamine by mast cells promoting osteoblastic activity); often alternating with areas of bone rarefaction

  Predilected sites:

  skull, spine, ribs, pelvis, humerus, femur

• @ Reticuloendothelial system

  • hepatomegaly

  • splenomegaly (43 61%)

  • lymphadenopathy: retroperitoneal, periportal, mesenteric

  • Budd-Chiari hepatic venoocclusive disease

  • reversed portal venous flow

  • cavernous transformation of portal vein

• @ Abdomen

  • nausea, vomiting, diarrhea

  • thickening of omentum, + mesentery

  • ascites:

    • transudative secondary to liver disease

    • exudative from mast cell proliferation of peritoneum

• @ Small bowel

  • generalized irregular distorted nodular thickened folds wall thickening (due to infiltration by mast cells, lymphocytes, plasma cells)

  • diffuse pattern of 2 3-mm sandlike mucosal nodules

  • urticaria-like lesions of gastric + intestinal mucosa

Dx:	skin/bone marrow biopsy; jejunal biopsy demonstrates an excess of mast cells
Cx:	Peptic ulcer disease (release of histamine increases gastric acid secretion) Leukemia
Rx:	antihistamines, histamine decarboxylase inhibitors, sodium chromoglycase; steroids; splenectomy (for symptomatic splenomegaly/hypersplenism)
DDx:	carcinoid, pheochromocytoma

P.855

Meckel Diverticulum

• = persistence of the omphalomesenteric duct (= vitelline duct), which usually obliterates by 5th embryonic week

• Most common congenital abnormality of the GI tract!

Incidence:	0.3 2 3% of population (at autopsy)
Age:	majority in children <10 years of age; M:F = 3:1
Histo:	contains ectopic mucosa in 50%: gastric/pancreatic/colonic mucosa Frequency of heterotopic gastric mucosa:    15 34% overall; 50% in symptomatic patients; in >95% with GI hemorrhage
Location:	within terminal 6 feet of ileum (= 30 100 cm from ileocecal valve); in 94% on antimesenteric border asymptomatic (20 40%)
RULE OF 2s:	in 2% of population symptomatic usually before age 2 located within 2 feet of ileocecal valve length of 2 inches

• NUC = Meckel scan (>85% sensitive, >95% specific, >83 88% accurate):

  • Tc-99m pertechnetate is excreted by mucoid cells of gastric mucosa, excretion is not dependent on presence of parietal cells

  N.B.:

  sensitivity drops after adolescence, because patients asymptomatic throughout childhood are less likely to have ectopic gastric mucosa

  • Preparation:

    • No irritative measures for 48 hours (contrast studies, endoscopy, cathartics, enemas, drugs irritating GI tract)

    • Fasting for 3 6 hours (results in decreased gastric secretion + diminished bowel peristalsis)

    • Evacuation of bowel + bladder prior to study

    Dose:	5 10 20 mCi (100 Ci/kg) Tc-99m pertechnetate (adult dose!)
    Radiation dose:	0.54 rad/2 mCi for thyroid; 0.3 rad/2 mCi for large intestine; 0.2 rad/2 mCi for stomach
    Imaging:	immediate continuous anterior imaging for 30 45 minutes/serial images in 5 10-minute intervals for up to 1 hour

  • small focal collection of tracer in RLQ appearing at the same time/shortly after gastric activity

  • tracer activity increases in intensity with time parallel to that of stomach

  • improved visualization through

    • pentagastrin = stimulates uptake (6 g/kg SC 20 minutes prior to pertechnetate)

    • cimetidine = inhibits secretion (maximum 300 mg/dose IV 1 hour prior)

    • glucagon = decreases peristalsis (50 g/kg IM 5 10 minutes prior)

  • poor visualization with use of perchlorate + atropine (= depressed uptake)

  • False-positive results:

    • Ectopic gastric mucosa in gastrogenic cyst, enteric duplication, normal small bowel, Barrett esophagus

    • Increased blood pool in AVM, hemangioma, hypervascular tumor, aneurysm

    • Duodenal ulcer, ulcerative colitis, Crohn disease, appendicitis, laxative abuse

    • Intussusception, intestinal obstruction, volvulus

    • Urinary tract obstruction, caliceal diverticulum

    • Anterior meningomyelocele

    • Poor technique

    mnemonic:

    HA GUIDI

    • Hemangioma

    • Appendicitis

    • Gastric ectopia

    • Urinary obstruction

    • Intussusception

    • Duplication of bowel

    • Inflammatory bowel disease

  • False-negative results:

    • Insufficient mass of ectopic gastric mucosa

    • Dilution of intraluminal activity (hemorrhage/hypersecretion)

    mnemonic:

    MIS

    • Malrotation of ileum

    • Irritable bowel in RLQ (rapid transit)

    • Small amount of ectopic gastric mucosa

• Enteroclysis:

  • elongated, smoothly marginated, clublike, intraluminal mass parallel to long axis of distal ileum = inverted Meckel diverticulum (20%)

  • 0.5 20-cm-long blind pouch on the antimesenteric border of ileum with junctional fold pattern

• Angio (59% accuracy):

  • presence of vitelline artery (= anomalous end branch of superior mesenteric artery) is PATHOGNOMONIC

• Cx (in 4 20 40%):

  • painless GI bleeding secondary to ulceration (in 95% due to heterotopic gastric mucosa) in children <5 years of age

  • Acute diverticulitis

  • Intestinal obstruction secondary to intussusception (diverticulum acts as lead point)/volvulus (when omphalomesenteric diverticulum attached to umbilicus by fibrous band) in older children/adults

  • Malignant tumor (rare): carcinoma, sarcoma, carcinoid

  • Chronic abdominal pain

Meconium Ileus

• = small bowel obstruction secondary to desiccated meconium pellets impacted in distal ileum

Age:

may develop in utero (in 15%)

Associated with:

• cystic fibrosis with tenacious + sticky meconium due to deficiency of pancreatic secretions (in almost 100%)

• Virtually all infants with meconium ileus prove to have cystic fibrosis

• 10 15% of infants with cystic fibrosis present with meconium ileus!

  P.856

  
  

  • Earliest clinical manifestation of cystic fibrosis!

• abdominal distension, bilious emesis

• failure to pass meconium within 48 hours

• numerous dilated small bowel loops without air-fluid levels (fluid not present)

• bubbly / frothy appearance of intestinal contents

• soap-bubble / applesauce appearance in RLQ (in 50 66%) due to admixture of gas with meconium

• multiple round/oval filling defects in distal ileum + colon

• functional microcolon (unused colon in antenatal obstruction)

OB-US:

• unusual echogenic intraluminal areas in small bowel (DDx: normal transient inspissated meconium)

• usually polyhydramnios

• fluid-filled dilated small bowel

Cx (in 40 50%):	volvulus, ischemia, necrosis, stenosis, atresia, perforation, meconium peritonitis, pseudocyst
Rx:	(1) Nonionic contrast media enema (because of risk of bowel perforation) (2) 17% Hypaque/Conray enema mixed with acetylcysteine (MucomystR) (3) GastrografinR enema with Tween 80 (attention to fluid + electrolyte balance)
DDx:	Hirschsprung disease, small bowel atresia with meconium ileus, meconium plug syndrome, small left colon syndrome, imperforate anus, obstruction from duplication cyst

Meconium Peritonitis

• = sterile chemical peritonitis secondary to perforation of bowel proximal to high-grade/complete obstruction that seals in utero due to inflammatory response

Incidence:	1:35,000 livebirths
Age:	antenatal perforation after 3rd month of gestation

Cause:

• Atresia (secondary to ischemic event) (50%)

  • of small bowel (usually ileum or jejunum)

  • of colon (uncommon)

• Bowel obstruction (46%)

  • meconium ileus

  • volvulus, internal hernia

  • intussusception, congenital bands, Meckel diverticulum

  • microcolon

• Hydrometrocolpos

  • Meconium peritonitis due to cystic fibrosis diagnosed in utero in 8% + at birth in 15 40%!

  • Intraperitoneal meconium may calcify within 24 hours!

Types:

• fibroadhesive type (most common):

  • = intense chemical reaction of peritoneum, which seals off the perforation

  • no evidence for active leak at birth

  • dense mass with calcium deposits

  • calcific plaques scattered throughout peritoneal cavity

• cystic type:

  • = cystic cavity formed by fixation of bowel loops surrounding the perforation site, which continues to leak meconium

  • cyst outlined by calcific rim

• generalized type:

  • perforation occurs immediately antenatally

  • active leakage of bowel contents

  • complicated ascites

• intraabdominal calcifications (conspicuously absent in cystic fibrosis):

  • peripherally calcified pseudocysts

  • small flecks of calcifications scattered throughout abdomen

  • larger aggregates of calcifications along inferior surface of liver/flank/processus vaginalis/scrotum

• obstructive roentgen signs following birth

• separation of bowel loops by fluid

• microcolon = unused colon

• meconium hydrocele producing labial mass

US:

• highly echogenic linear/clumped foci with posterior acoustic shadowing in scrotum

• snowstorm appearance = highly echogenic material throughout abdomen in between bowel loops

• ill-/well-defined homo-/heterogeneous encysted collections of meconium

OB-US (>18 weeks EGA):

• polyhydramnios (64 71%)

• fetal ascites (54 57%)

• bowel dilatation (27 29%)

• intraabdominal bright echogenic mass

• multiple linear/clumped foci of scattered calcifications (85%); may develop within 12 hours to 8 days after perforation

• meconium pseudocyst = well-defined hypoechoic mass surrounded by an echogenic calcified wall (= contained perforation)

DDx:	(1) Intraabdominal teratoma (2) Fetal gallstones (3) Isolated liver calcifications
Mortality:	up to 62%
Prognosis:	generally good; surgery may not be required when perforation site is completely healed

Meconium Plug Syndrome

• = local inspissation of meconium leading to low colonic obstruction; probably related to small left colon syndrome as part of same spectrum of functional immaturity

Age:	newborn infant (symptomatic within first 24 hours of life)
Cause:	cystic fibrosis (25%), Hirschsprung disease, prematurity, maternal magnesium sulfate treatment

• abdominal distension

• vomiting

• failure to pass meconium

• distended transverse + ascending colon + dilated small bowel (proximal to obstruction)

• small left colon with change in caliber at splenic flexure

• occasionally bubbly appearance in colon (DDx: submucosal air in necrotizing enterocolitis)

• presacral pseudotumor (no gas in rectum)

BE:

• double-contrast effect = barium between meconium plug + colonic wall

Rx:	water-soluble enema
DDx:	Hirschsprung disease

P.857

Melanosis Coli

• = benign brown-black discoloration of colonic mucosa

Incidence:	10% of autopsies
Cause:	chronic anthracene cathartic usage

• asymptomatic

Prognosis:

no malignant potential

M n trier Disease

• = GIANT HYPERTROPHIC GASTRITIS = HYPERPLASTIC GASTROPATHY

• = characterized by excessive mucus production and

TRIAD of	(1) Giant mucosal hypertrophy (2) Hypoproteinemia (3) Hypochlorhydria
Path:	mucosal thickness up to 6 mm (normal range: 0.6 1.0 mm)
Histo:	hyperplasia of glandular tissue + microcyst formation
Age:	20 70 years; M:F = 2:1
Associated with:	benign gastric ulcer (13 72%)

• epigastric pain, vomiting, weight loss

• gastrointestinal bleeding

• protein-losing enteropathy with hypoproteinemia + peripheral edema

• absent/decreased acid secretion (>50%)

Location:

throughout fundus + body, particularly prominent along greater curvature, antrum usually spared (DDx to lymphoma: usually in antrum)

• markedly enlarged + tortuous gastric rugae in spite of adequate gastric distension:

  • relatively abrupt demarcation between normal antrum + abnormal fundus + body

• marked hypersecretion (mucus)

• preserved pliability of stomach

CT:

• wall thickening of proximal stomach

• nodular symmetric folds

Cx:	development of gastric cancer reported
DDx:	lymphoma, polypoid variety of gastric carcinoma, acute gastritis, chronic gastritis, gastric varices

Mesenteric Lymphadenitis

• = clinical entity whose symptoms relate to benign inflammation of lymph nodes in the bowel mesentery

Cause:	Yersinia enterocolitica, Y. pseudotuberculosis, viral infection
Age:	children, young adults

• nausea, vomiting, diarrhea, fever

• diffuse/RLQ pain + tenderness

Location:

usually RLQ (immediately anterior to right psoas muscle in 78%, small bowel mesentery in 56%)

• enlarged mesenteric lymph nodes

• isolated ileal wall thickening (33%)

• colonic wall thickening (18%)

N.B.:	visualization of entire normal appendix is necessary to differentiate from acute appendicitis!
DDx:	appendicitis (enlarged nodes immediately anterior to right psoas muscle in 40 82%, nodes less numerous + smaller), Crohn disease

Mesenteric Ischemia

• = BOWEL ISCHEMIA

Etiology:

• arterial occlusion: atheromatous disease, thromboembolic disease, dissecting aortic aneurysm, fibromuscular hyperplasia, arteritis, endotoxin shock, hypoperfusion (shock, hypovolemia), disseminated intravascular coagulation, direct trauma, aortic surgery, stent placement, therapeutic embolization, radiation, antiphospholipid antibody syndrome

  • occlusive mesenteric infarction (90% mortality)

    • Embolus (40 50%) just distal to middle colic a.

    • SMA thrombosis (20 40%) at origin + site of atherosclerotic narrowing (ostium stenosis)

  • nonocclusive mesenteric ischemia (10% mortality)

    • Preexisting atherosclerosis with systemic low-flow state, cardiac failure/arrhythmia, intraoperative hypotension

    • Bowel vasoconstriction = vasospasm (reflex hypotension, digitalis, ergot preparation, vasopressin, amphetamine, cocaine), pheochromocytoma, familial dysautonomia

    • Shock bowel = diffuse small bowel ischemia in hypovolemia and hemorrhagic/cardiogenic/septic shock (due to increased bowel permeability to macromolecules + albumin)

      • diffuse bowel wall thickening

      • persistent increased enhancement on CT (due to slowed perfusion and washout + interstitial leakage of contrast material)

      • accumulation of intraluminal fluid (due to failed resorption capacity)

• venous occlusion (<10%): young patient, often following abdominal surgery

  Location:

  superior mesenteric vein > inferior mesenteric vein > portal vein

• bowel obstruction: strangulation by adhesions or bands mesenteric vein thrombosis, incarceration of hernia, volvulus, intussusception, pronounced overdistension (prestenotic, distension colitis), ischemic colitis due to endoscopy/enemas/colonic carcinoma (1 7%)

• vasculitis: polyarteritis nodosa (50 70%)

  • relatively long segment of bowel involved

  • multiple skip areas in nonsegmental distribution

  • involvement of duodenum is indicative

• abdominal inflammation: pancreatitis, appendicitis, diverticulitis, diffuse peritonitis, parasitic infestation

• cytotoxic drugs: long-term immunosuppressive drugs for rejection, chemotherapy for leukemia/lymphoma

• radiation: >4,500 cGy

Prevalence:

5% for SMA; 4% for celiac artery; 11% for inferior mesenteric artery

Pathophysiology:

• ischemia leads to

  • inflammatory response (cytokines, platelet-activating factor, tumor necrosis factor released from activated neutrophils, platelets, mast cells, endothelial cells)

  • breakdown of mucosal barrier from

    • mild superficial necrosis limited to mucosa (mucosal ulcer) = partial mural bowel ischemia, to

    P.858

    
    

    • life-threatening continuous necrosis of all bowel wall layers = transmural bowel infarction

  • invasion of bacteria with bacteremia + sepsis

  • strictures

Acute Mesenteric Ischemia

Cause:

• acute occlusive SMA embolus (in >50%): usually lodges at bifurcation of middle colic artery + SMA

• SMA thrombosis (4 18%; nonocclusive in 25%): frequently involves the proximal SMA

• SMA dissection (due to cystic medial necrosis, fibromuscular dysplasia)

• venous occlusion in 5 10 15% (due to hypercoagulability, trauma, portal hypertension, infection, carcinoma, oral contraceptives)

• first crampy, then continuous abdominal pain with acute event

• cardiac disease predisposing to embolization

• gut emptying (vomiting/diarrhea)

• WBC >12,000/ l with left shift (80%)

• gross rectal bleeding

Location:

(a) any segment of small bowel
(b) distal transverse colon, splenic flexure, cecum (most common)

Consequences:

• dependent on magnitude of insult, duration of process, adequacy of collaterals

• reversible ischemia

  • Complete restitution of bowel wall secondary to abundant collaterals

  • Healing with fibrosis + stricture formation

• irreversible ischemia

  • Transmural infarction with bowel perforation

Plain film:

• gasless abdomen (= fluid-filled loops from exudation) in 21%

• bowel distension to splenic flexure (= perfusion territory of SMA) in 43%

• thumbprinting (36%) = thickening of bowel wall + valvulae (edema)

• small bowel pseudoobstruction (most frequently in thrombosis)

• pneumatosis = dissection of luminal gas into bowel wall (28%)

• mesenteric + portal vein gas (14%)

• ascites (14%)

Barium:

• scalloping/thumbprinting = thickening of wall + valvulae

• picket fencing

• separation + uncoiling of loops

• narrowed lumen

• circumferential ulcer

CT (26 73 82% sensitive):

• circumferential bowel wall thickening (28 52 96%) >3 5 mm depending on degree of distention:

  • target sign = alternating layers of high and low attenuation (from submucosal edema hemorrhage superinfection) in

    • ischemic colitis (94%)

    • reversible mesenteric ischemia (80%)

    • mesenteric infarction (26 38%)

  • spastic contractions of colon in mild mucosal ischemia

  • Least specific sign

  • No correlation with the severity of ischemic damage

• thinning of bowel wall (in acute arterio-occlusive transmural infarction) if it becomes gangrenous

• focal/diffuse bowel dilatation (10 56 91%) with gas (43%)/fluid (29%) due to interruption of peristaltic activity (destruction of intramural nerves + intestinal musculature)/irreversible transmural ischemic damage

• bowel wall attenuation:

  • decreased, usually homogeneously (due to edema)

  • increased (due to hemorrhage)

• variable enhancement pattern:

  • diminished enhancement of bowel wall (due to compromised blood flow)

  • absent enhancement of bowel wall (in 18%, 62% sensitive, 96% specific)

  • engorgement of mesenteric vessels = venous congestion secondary to stasis

  • increased wall enhancement (due to hyperemia in outflow obstruction from mesenteric venous occlusion/during reperfusion after arteriogenic bowel ischemia/in shock bowel) is a good prognostic indicator (33% sensitive, 71% specific)

  • delayed + persistent enhancement (due to delayed venous return and arteriospasm)

• increased attenuation of mesenteric fat from mesenteric edema (in 68%, 58% sensitive, 79% specific)

• mesenteric fluid (88% sensitive, 90% specific)

• ascites (in 43 88%, 75% sensitive, 76% specific)

• pneumatosis intestinalis (in 6 28%, 3 14% specific) = dissection of luminal gas into bowel wall across compromised mucosa signaling irreversible disease:

  • small isolated gas bubbles within wall

  • broad rims of air dissecting the entire bowel wall into two layers

• portal venous gas (5 13 36%)/mesenteric vein gas (28%) = propagation of intramural gas into mesenteric venous system

• pneumoperitoneum (7%) = perforation of infarcted bowel segment

• arterial occlusion:

  • hyperattenuating SMA on NECT

  • filling defect with ring enhancement on CECT

  • thumbprinting (26%) = thickening of bowel wall

  • lack of bowel wall enhancement with arterial occlusion

  • concurrent embolic infarction of kidney/spleen

• venous thrombosis (15%):

  • enlarged diameter + increased attenuation of SMV on NECT

  • filling defect in SMV/portal vein thrombosis on CECT

  • thickened intestinal wall (64%) due to edema

  • waterlogging with marked contrast enhancement of mesentery + bowel wall

P.859

Cx:

bowel necrosis (with occlusion of small vasa recta disallowing collateral flow)

Common pitfalls:

• Spastic colon misinterpreted a s simple contraction, issue resolved by repeat CT with enema)

• Widely distended colonic segment with a wall thickness of 3 5 mm misinterpreted as normal

• Small bowel dilatation + air-fluid levels misinterpreted as ileus/pseudoobstruction

Angio (AP and LAT views):

• occlusion/vasoconstriction/vascular beading

• embolus lodged at major branching points distal to first 3 cm of SMA

Rx for nonocclusive mesenteric ischemia:

• via SMA catheter 60 mg papaverin slowly injected followed by papaverin infusion of 1 mg/min

NUC:

• IV/IA Tc-99m sulfur colloid/labeled leukocytes, Gacitrate, Tc-99m pyrophosphate:

  • tracer accumulation 5 hours after onset of ischemia (more intense uptake with transmural infarcts)

• intraperitoneal injection of Xe-133 in saline is absorbed by intestine:

  • decreased washout with abnormal perfusion of strangulated bowel

Prognosis:

• Massive infarction of small + large bowel if mesenteric embolization occurs proximal to middle colic artery (= limited collateral flow)

• Focal segments of intestinal ischemia if mesenteric embolization occurs distal to middle colic artery (= good collateral flow)

Local Cx:	bleeding, intestinal perforation, abscess formation, peritonitis
Systemic Cx:	hemoconcentration, acidosis, DIC, bone marrow suppression, multiple organ failure (including heart + kidneys)
Mortality:	70 80 92% for intestinal infarction
DDx:	typhlitis, Crohn disease, infectious/ulcerative colitis, proctosigmoiditis, sigmoid diverticulitis, other causes of pneumatosis intestinalis/portal venous gas

Chronic Mesenteric Ischemia

• = ABDOMINAL ANGINA

• = intermittent mesenteric ischemia in severe arterial stenosis with inadequate collateralization provoked by food ingestion

• postprandial abdominal pain 15 20 minutes after food intake (due to gastric steal diverting blood flow away from intestine)

• fear of eating large meals

• weight loss, malabsorption

• reflex emptying of bowel after eating

Barium:

• Subacute:

  • flattening of one border

  • pseudosacculation/pseudodiverticula on antimesenteric border

• Chronic:

  • 7 10-cm-long smooth pliable strictures

  • dilatation of gut between strictures

  • thinned + atrophic valvulae

  Cx:

  obstruction

Duplex US:

• celiac trunk occlusion + retrograde perfusion of hepatic artery through SMA

• PSV >300 cm/sec and EDV >45 cm/sec in SMA

• peak systolic velocity >160 cm/sec in celiac trunk for >50% stenosis (57% sensitivity, 100% specificity) during fasting state

Mesenteric Venous Thrombosis

Cause:

• Infection: sepsis, diverticulitis, appendicitis, Crohn disease, peritonitis, abdominal abscess

• Hypercoagulable state: antithrombin III/protein C or S deficiency, oral contraceptives

• Trauma

• Mechanical: volvulus, bowel obstruction, postoperative state

Location:

SMV > IMV (6%)

• subacute symptomatology over 1 4 weeks

• severe abdominal pain with rebound/guarding

• nausea, vomiting, diarrhea

• hematemesis, hematochezia (after bowel necrosis)

• ileus

• ascites

• bowel wall thickening with thumbprinting (bowel wall thickening usually more pronounced compared to arterio-occlusive disease)

• dilated vein with echogenic thrombus

Mesothelial Cyst

• = MESENTERIC/OMENTAL CYST

Etiology:	failure of mesothelial peritoneal surfaces to coalesce
Path:	unilocular thin-walled cyst usually with serous, occasionally chylous/hemorrhagic fluid contents
Histo:	lined by mesothelial cells + surrounded by thin layer of fibrous tissue
Location:	small bowel, mesentery (78%), mesocolon

• asymptomatic

• single cyst up to several cm in size

• omental cysts may be pedunculated

CT:

• near-water density/soft-tissue density

• fluid levels related to fat + water components

Cx:	torsion, hemorrhage, intestinal obstruction
DDx:	lymphangioma (septations)

Metastases to Colon

Spread:

• Hematogenous

  • submucosal masses/bull's-eye lesions

  • diffusely infiltrating lesions mimicking inflammatory bowel disease

• Direct invasion by contiguous tumor

  ovary	inferior border of sigmoid
  left kidney	splenic flexure
  pancreatic tail	splenic flexure
  pelvis (uterus, bladder)	anterior border of rectum
  prostate	rectosigmoid

P.860




• Direct invasion along mesenteric reflections

  stomach	transverse colon superior margin
  pancreas	transverse colon inferior margin
  omental cake	transverse colon superior margin

• Intraperitoneal seeding

  Origin:

  ovarian, gastric, colonic, pancreatic cancers (most commonly)

  • Classic sites of seeding:

    • pouch of Douglas (50%):

      • anterior border of rectosigmoid

    • lower small bowel mesentery (40%):

      • medial border of cecum

    • sigmoid mesocolon (20%):

      • superior border of sigmoid colon

    • right paracolic gutter (10%):

      • lateral border of ascending colon

Metastases to Small Bowel

Origin:

colon > stomach > breast > ovary > uterine cervix > melanoma > lung > pancreas

Spread:

• Intraperitoneal seeding: primary mucinous tumor of ovary, appendix, colon; breast cancer

• Hematogenous dissemination with submucosal deposits: malignant melanoma, breast carcinoma, lung carcinoma, Kaposi sarcoma

• Direct extension from adjacent neoplasm:

  • ovary, uterus, prostate, pancreas, colon, kidney

• fixation + tenting + transverse stretching (= across long axis) of folds secondary to mesenteric + peritoneal infiltration (most common form)

UGI:

• single mass protruding into lumen resembling annular carcinoma

• bull's-eye lesions = multiple polypoid masses with sizable ulcer craters

• obstruction from kinking/annular constriction/large intraluminal mass

• compression by direct extension of primary tumor/involved nodes

CT:

• soft-tissue density nodules/masses

• sheets of tissue causing thickening of bowel wall + mesenteric leaves

• fixation + angulation of bowel loops (in tumors with desmoplastic response)

• ascites

Metastases to Stomach

Organ of origin:

malignant melanoma, breast, lung, colon, prostate, leukemia, secondary lymphoma

• GI bleeding + anemia (40%)

• epigastric pain

• solitary mass (50%)

• multiple nodules (30%)

• linitis plastica (20%): especially breast

• multiple umbilicated nodules: melanoma

Midgut Volvulus

• = torsion of entire gut around SMA due to a short mesenteric attachment of small intestine in malrotation

Age:

neonate/young infant (= acute intestinal obstruction); occasionally older child/adult (= chronic intestinal obstruction) In 20% associated with: (1) Duodenal atresia
(2) Duodenal diaphragm
(3) Duodenal stenosis
(4) Annular pancreas

Pathophysiology:

• degree of twisting can change due to natural movement of bowel + determines symptomatology; severe volvulus (= twist of 3 and a half turns) causes bowel necrosis

• acute symptoms within first 3 weeks of life in 75% (MEDICAL EMERGENCY): bilious vomiting (postprandial, intermittent, projectile) is HALLMARK; abdominal distension; shock

• intermittent obstructive symptoms in older child: recurring attacks of nausea, vomiting, and abdominal pain

• failure to thrive (hypoproteinemic gastroenteropathy as a result of lymphatic + venous obstruction)

• currant jelly stools/melena (implying vascular compromise)

Plain film:

• dilated air-filled duodenal bulb + paucity of gas distally

• double bubble sign = air-fluid levels in stomach + duodenum

• isolated collection of gas-containing bowel loops distal to obstructed duodenum = gas-filled volvulus = closed-loop obstruction (from nonresorption of intestinal gas secondary to obstruction of mesenteric veins)

UGI:

N.B.:

exclude perforation on plain films!

• dilated proximal duodenum terminating in a distinctive conical shape

• duodenal-fold thickening + thumbprinting (mucosal edema + hemorrhage)

• duodenojejunal junction (ligament of Treitz) located lower than duodenal bulb + to the right of expected position

• spiral course of midgut loops beyond point of obstruction = apple-peel/twisted ribbon/corkscrew appearance (in 81%)

• abnormally high position of cecum (on barium enema)

CT:

• whirl-like pattern of small bowel loops + adjacent mesenteric fat converging to the point of torsion (during volvulus)

• transposition of SMA/SMV = SMV to the left of SMA (NO volvulus)

• chylous mesenteric cyst (from interference with lymphatic drainage)

US:

• clockwise whirlpool sign = color Doppler depiction of superior mesenteric vein wrapping clockwise around superior mesenteric artery

• distended proximal duodenum with arrowhead-type compression over spine

• superior mesenteric vein to the left of SMA

• thick-walled bowel loops below duodenum + to the right of spine associated with free intraperitoneal fluid

P.861

Angio:

• barber pole sign = spiraling of SMA

• tapering/abrupt termination of mesenteric vessels

• marked vasoconstriction + prolonged contrast transit time

• absent venous opacification/dilated tortuous superior mesenteric vein

Cx:	intestinal ischemia + necrosis in distribution of SMA with occlusion of lymphatics, SMV + SMA (bloody diarrhea, ileus, abdominal distension)
DDx:	pyloric stenosis (same age group, no bilious vomiting)

Mucocele of Appendix

Mucocele

• = distension of appendix with sterile mucus

Etiology:

• (perhaps) cystic dilatation of lumen secondary to obstruction by fecolith, foreign body, carcinoid, endometriosis, adhesions, volvulus

• mucosal hyperplasia (25%)

• mucinous cystadenoma due to hyperplasia with epithelial atypia (63%)

• mucinous cystadenocarcinoma with stromal invasion (12%)

• accumulation of thick mucus in cystic fibrosis

Incidence:	0.07 0.3% of appendectomy specimens
Mean age:	55 years; M:F = 1:4
Associated with:	colonic adenocarcinoma (6-fold risk), mucin-secreting tumor of ovary

• asymptomatic (25%)

• palpable mass (in up to 50%)

• acute/chronic right lower quadrant pain

• globular, smooth-walled, broad-based mass invaginating into cecum

• nonfilling of the appendix on BE

• peripheral punctate/rimlike calcifications frequent

CT:

• round sharply defined paracecal mass with homogeneous content of near-water/soft-tissue attenuation (depending on amount of mucin)

US:

• purely cystic/cystic with fine internal echoes/complex cystic mass with high-level echoes

• gravity-dependent echoes = layering of protein macroaggregates/inspissated mucoid material

• acoustic shadowing if calcifications present

NUC:

• intense early gallium uptake (affinity to acid mucopolysaccharides of mucus)

Cx:

(1) Rupture with pseudomyxoma peritonei
(2) Torsion with gangrene + hemorrhage
(3) Herniation into cecum with bowel obstruction
(4) Intussusception

Myxoglobulosis

• = rare variant of mucocele of the appendix characterized by clusters of pearly white mucous balls intermixed with mucus

• usually asymptomatic

• may appear as acute appendicitis

• multiple 1 10-mm small rounded annular, nonlaminated calcified spherules (PATHOGNOMONIC)

DDx:

inverted appendiceal stump, acute appendicitis, carcinoma of the cecum

Necrotizing Enterocolitis

• = NEC = ischemic bowel disease secondary to hypoxia, perinatal stress, infection (endotoxin), congenital heart disease

Incidence:	most common GI emergency in premature infants
Age:	develops 2 3 days after birth; in 90% within first 10 days of life
Path:	acute inflammation + mucosal ulceration + widespread transmural necrosis
Organism:	not yet isolated; often occurs in miniepidemics within nursery
Predisposed:	premature infant (50 80%), Hirschsprung disease, bowel obstruction (small bowel atresia, pyloric stenosis, meconium ileus, meconium plug syndrome)

• abdominal distension, bilious emesis

• blood-streaked stools (in 50%); explosive diarrhea

• mild respiratory distress

• generalized sepsis

Location:

usually in terminal ileum (most commonly involved), cecum, right colon; rarely in stomach, upper bowel

• distension of small bowel and colon (loops wider than vertebral body L1) air-fluid levels, commonly in RLQ (1st sign)

• disarrayed bowel gas pattern (no longer normal array of polygons)

• tubular loops of bowel

• bowel wall thickening + thumbprinting

• fixed bowel = persistent abnormal loop of bowel without change on supine vs. prone films/for >24 hours

• pneumatosis intestinalis (80%):

  • in curvilinear shape (= subserosal) or

  • bubbly/cystic (= submucosal gas collection from gas-forming organisms/dissection of intraluminal gas)

• bubbly appearance of bowel due to gas in wall/intraluminal gas/fecal matter (intraluminal contents are composed of blood, sloughed colonic mucosa, intraluminal gas, some fecal material)

• gas in portal venous system (frequently transient, does not imply hopeless outcome)

• ascites

• pneumoperitoneum (immediate surgery required)

N.B.:	barium enema is contraindicated! May be used judiciously in selected cases with radiologic + clinical doubt!
Cx:	(1) Inflammatory stricture after healing in 10 30%, in 30% multiple, in 80% in left colon (BE follow-up in survivors) (2) Bowel perforation in 12 32%

Pelvic Lipomatosis + Fibrolipomatosis

• = nonmalignant overgrowth of adipose tissue with minimal fibrotic + inflammatory components compressing soft-tissue structures within pelvis

Incidence:	0.6 1.7:100,000
Cause:	unknown; UTIs, obesity, endocrine dysfunction
Age:	9 80 years (peak 25 60 years); M:F = 10:1; NO racial predominance for Blacks ( ); obesity NOT contributing factor

P.862

• often incidental finding

• urinary frequency, dysuria, nocturia, hematuria

• flank pain, suprapubic tenderness

• recurrent urinary tract infections

• low back pain, fever

• constipation, tenesmus, rectal bleeding, ribbonlike stools with mucus

• edema of lower extremities

• elongation + narrowing of rectum

• elevation of rectosigmoid + sigmoid colon out of pelvis

• increase in sacrorectal space >10 mm

• stretching of sigmoid colon

• elongation + elevation of urinary bladder with symmetric inverted pear shape

• elongation of posterior urethra

• pelvic lucency; CT confirmatory

• medial/lateral displacement of ureters

Cx of fibrolipomatosis:

• Ureteral obstruction (40% within 5 years)

• IVC obstruction

Rx:

urinary diversion to prevent end stage renal disease

Peritoneal Mesothelioma

• = only primary tumor of peritoneum arising from mesothelial cells lining peritoneal cavity

Age:	55 66 years; M > F
Associated with:	asbestos exposure
Spread:	intraperitoneal along serosal surfaces; direct invasion of liver, pancreas, bladder, bowel
Location:	pleura (67%), peritoneum (30 40%), pericardium (2.5%), processus vaginalis (0.5%)

• thickening of mesentery, omentum, peritoneum, bowel wall

• nodular masses in anterior parietal peritoneum becoming confluent and cakelike

• disproportionately small amount of ascites

• areas of calcification (rare)

CT:

• nodular irregular thickening of peritoneal surfaces

• localized masses

• infiltrating sheets of tissue

• foci of calcifications

• ascites of near-water density

• stellate configuration of neurovascular bundles

• pleated thickening of mesenteric leaves

NUC:

• diffuse uptake of gallium-67

Prognosis:

extremely poor due to advanced disease at presentation (most patients die within 1 year)

Cystic Mesothelioma

• = rare benign neoplasm without metastatic potential but tendency for local recurrence (in 27 50%)

Path:

multiple thin-walled cysts lined by mesothelial cells + filled with watery fluid; intermediate form between benign adenomatoid tumor + malignant peritoneal mesothelioma

• Not associated with asbestos exposure!

Median age:	37 years; M F
Location:	any peritoneal/omental surface, most frequently in pelvis

• contains watery fluid

• uni-/multilocular cystic tumor (cysts of 1 mm to 6 cm) without calcifications

DDx:

lymphangioma, ovarian carcinoma

Peritoneal Metastases

• = PERITONEAL CARCINOMATOSIS

• = intraabdominal spread of malignant tumors

Origin:

(a) common: ovary, stomach, colon (b) less common: pancreas, uterus, bladder

• massive ascites

• desmoplastic reaction at (a) anterior border of rectum (Blumer shelf), (b) mesenteric side of terminal ileum

CT:

• increased density of linear network in mesenteric fat

• loculated fluid collections in peritoneal cavity

• apparent thickening of mesenteric vessels (= fluid within leaves of mesentery)

• adnexal mass of cystic/soft-tissue density (= Krukenberg tumor)

• small nodular densities on peritoneal surface

• omental cake = thickening of greater omentum

• lobulated mass in pouch of Douglas

• calcified peritoneal implants in serous cystadenocarcinoma of ovary (in up to 40% with stage III/IV disease)

Peutz-Jeghers Syndrome

• [Johannes Peutz (1886 1957), internist in Den Haag, Holland]

• [Harold Jeghers (1904 1990), internist in Boston, USA]

• = rare autosomal dominant disease with incomplete penetrance characterized by intestinal polyposis + mucocutaneous pigmentation (= hamartomatosis); often spontaneous mutation

Incidence:	1:7,000 live births; in 50% familial, in 50% sporadic; most frequent of polyposis syndromes to involve small intestines
Age:	25 years at presentation (range 10 30 years); M:F = 1:1
Path:	multiple small sessile/large pedunculated polyps
Histo:	benign hamartomatous polyp with smooth muscle core arising from muscularis mucosae + extending treelike into lamina propria of polyp; misplaced epithelium in submucosa, muscularis propria, sub-serosa frequently surrounding mucin-filled spaces

• mucocutaneous pigmentation (similar to freckles):

  • = 1 5-mm small elongated melanin spots on mucous membranes (lower lips, gums, palate) + facial skin (nose, cheeks, around eyes) + volar aspects of toes and fingers (100%), becoming noticeable in first few years of life

• cramping abdominal pain (small bowel intussusception in 47%)

• rectal bleeding, melena (30%)

• prolapse of polyp through anus

• chronic hypochromic microcytic anemia

Location:

small bowel (jejunum + ileum > duodenum) > colon > stomach; mouth + esophagus spared

• @ Small bowel (>95%)

  • multiple usually broad-based polyps separated by wide areas of intervening flat mucosa

  P.863

  
  

  • multilobulated surface of larger polyps

  • myriad of 1 2-mm nodules of up to several cm = carpet of polyps

  • intussusception usually confined to small bowel

• @ Colon + rectum (30%)

  • multiple scattered 1 30-mm polyps; NO carpeting

• @ Stomach + duodenum (25%)

  • diffuse involvement with multiple polyps

• @ Respiratory + urinary tract

  • adenoma of bronchus + bladder

Cx:

• Transient intussusception (pedunculated polyp)

• Carcinoma of GI tract (2 3%)

• Carcinoma of pancreas (13%)

• Carcinoma of breast (commonly bilateral + ductal)

• Ovarian tumor (5%), commonly bilateral: sex cord-stromal tumor of ovary (almost in 100% of patients), mucinous cystic tumor, cystadenoma, granulosa cell tumor

• Endometrial cancer: adenoma malignum of cervix

  • (= minimal deviation adenocarcinoma = low-grade mucinous tumor of cervix)

• Testicular tumor: feminizing Sertoli cell tumor

Rx:	(1) Endoscopic removal of all polyps >5 mm (2) Surgery is reserved for obstruction, severe bleeding, malignancy
Prognosis:	decreased life expectancy (risk of cancer approaching 40% by 40 years of age)
DDx:	familial adenomatous polyposis, juvenile polyposis (similar age), Cowden syndrome, Cronkhite-Canada syndrome

Postcricoid Defect

• = variable defect seen commonly in the fully distended cervical esophagus; no pathologic value

Etiology:	redundancy of mucosa over rich postcricoid submucosal venous plexus
Incidence:	in 80% of normal adults
Location:	anterior aspect of esophagus at level of cricoid cartilage

• tumor-/weblike lesion with variable configuration during swallowing

DDx:

submucosal tumor, esophageal web (persistent configuration)

Postinflammatory Polyposis

• = PSEUDOPOLYPOSIS

• = reepithelialized inflammatory polyps as sequelae of mucosal ulceration

Etiology:	ulcerative colitis (10 20%); granulomatous colitis (less frequent); schistosomiasis (endemic); amebic colitis (occasionally); toxic megacolon
Pathogenesis:	ulcerative undermining of strips of mucosa with reepitheliazation of denuded surfaces of tags + bowel wall
Location:	most common in left hemicolon, may occur in stomach/small intestine

• sessile + frondlike appearance (often)

• filiform polyposis = multiple wormlike projections only attached at their bases (CHARACTERISTIC)

Prognosis:	NO malignant potential
DDx:	familial polyposis (polyps terminate in bulbous heads)

Presbyesophagus

• = defect in primary peristalsis + LES relaxation associated with aging

Incidence:	15% in 7th decade; 50% in 8th decade; 85% in 9th decade
Associated with:	hiatus hernia, reflux

• usually asymptomatic

• impaired/no primary peristalsis

• often repetitive nonperistaltic tertiary contractions in distal esophagus

• mild/moderate esophageal dilatation

• poor LES relaxation

DDx:

diabetes, diffuse esophageal spasm, scleroderma, esophagitis, achalasia, benign stricture, carcinoma

Progressive Systemic Sclerosis

• = PSS = multisystem connective tissue disorder (collagen-vascular disease) of unknown etiology characterized by widespread disorder of the microvasculature and overproduction of collagen causing exuberant interstitial fibrosis with atrophy + sclerosis of many organ systems

• = SCLERODERMA = variety of skin disorders associated with hardening of skin;

  • by extent of cutaneous involvement divided into:

    • DIFFUSE SCLERODERMA

      • tends to involve older women;

      • interstitial pulmonary fibrosis more severe;

      • organ failure more likely

    • SYSTEMIC SCLEROSIS WITH LIMITED SCLERODERMA (formerly CREST syndrome)

      • CREST features more common; pulmonary arterial hypertension more common + more severe)

May be associated with:

• other connective tissue diseases (especially SLE and polymyositis/dermatomyositis)

Cause:	autoimmune condition with genetic predisposition, may be initiated by environmental antigen (eg, toxic oil syndrome in Spain through ingestion of adulterated rape seed oil/ingestion of L-tryptophan)
Peak age:	30 50 years; M:F = 1:3
Histo:	vasculitis + submucosal fibrosis extending into muscularis, smooth muscle atrophy (initially hypertrophy and finally atrophy of collagen fibers)
CREST:	Calcinosis of skin Raynaud phenomenon Esophageal dysmotility Sclerodactyly Telangiectasia

• antinuclear antibodies (30 80%):

  • centromere antibody (ACA) specific for limited disease

  • anti topoisomerase-1 (= antiScl-70) identifies patients with diffuse cutaneous disease

• antibodies to extracellular matrix proteins and type I + IV collagen

• rheumatoid factor (35%)

• LE cells (5%)

• weakness, generalized debility

Prognosis:

50 67% 5-year survival rate

P.864

Gastrointestinal Scleroderma (in 40 45%)

• Third most common manifestation of scleroderma (after skin changes + Raynaud phenomenon)

• May precede other manifestations!

• abdominal pain, diarrhea

• multiple episodes of pseudoobstruction

• hepatomegaly

• @ Esophagus (in 42 95%)

  • First GI tract location to be involved!

  • dysphagia (50%), heartburn (30%)

  • normal peristalsis above aortic arch (striated muscle in proximal 1/3 of esophagus)

  • hypotonia/atony + hypokinesia/aperistalsis in lower 2/3 of esophagus (>50%)

  • deficient emptying in recumbent position

  • thin/vanished longitudinal folds

  • mild to moderate dilatation of esophagus

  • chalasia (= patulous lower esophageal sphincter)

  • gastroesophageal reflux (70%)

  • erosions + superficial ulcers (from asymptomatic reflux esophagitis: NO protective esophageal contraction)

  • fusiform stricture usually 4 5 cm above gastroesophageal junction (from reflux esophagitis)

  • esophageal shortening + sliding hiatal hernia

  Cx:

  peptic stricture, aspiration, Barrett esophagus, adenocarcinoma

• @ Stomach (less frequent involvement)

  • gastric dilatation

  • decreased motor activity + delayed emptying

• @ Small bowel (in up to 45%)

  • PSS is rapidly progressing once small intestine is involved!

  • malabsorption (delayed intestinal transit time + bacterial overgrowth)

  • marked dilatation of small bowel (in particular duodenum = megaduodenum, jejunum) simulating small bowel obstruction

    CAVE:

    misdiagnosis of obstruction may lead to exploratory surgery!

  • abrupt cutoff at SMA level (atrophy of neural cells with hypoperistalsis)

  • prolonged transit time with barium retention in duodenum up to 24 hours

  • hidebound/accordion pattern (60%) = sharply defined folds of normal thickness with decreased intervalvular distance (tightly packed folds) within dilated segment (due to predominant involvement of circular muscle)

  • pseudodiverticula (10 40%) = asymmetric sacculations with squared tops + broad bases on mesenteric side (due to eccentric smooth muscle atrophy)

  • pneumatosis cystoides intestinalis + pneumoperitoneum (occasionally)

  • excess fluid with bacterial overgrowth (= pseudo blind loop syndrome )

  • normal mucosal fold pattern

  Cx:

  intussusception without anatomic lead point

• @ Colon (up to 40 50%)

  • constipation (common), may alternate with diarrhea

  • pseudosacculations + wide-mouthed diverticula on antimesenteric side (formed by repetitive bulging through atrophic areas) in transverse + descending colon

  • eventually complete loss of haustrations (simulating cathartic colon)

  • marked dilatation (may simulate Hirschsprung disease)

  • stercoral ulceration (from retained fecal material)

Cx:	life-threatening barium impaction
DDx:	(1) Dermatomyositis (similar radiographic findings) (2) Sprue (increased secretions, segmentation, fragmentation, dilatation most significant in midjejunum, normal motility) (3) Obstruction (no esophageal changes, no pseudodiverticula) (4) Idiopathic intestinal pseudoobstruction (usually in young people)

Pulmonary Scleroderma (in 10 66%)

Path:	almost 100% involvement in autopsy series
Histo:	thickening of basement membrane of alveoli + small arteries and veins; pattern of usual interstitial pneumonia/nonspecific interstitial pneumonitis

• slightly productive, mostly dry cough

• exertional progressive dyspnea

• hematemesis

• pulmonary function abnormalities in the absence of frank roentgenographic changes (typical dissociation of clinical, functional, and radiologic evidence)

• pericarditis

Location:

peripherally, most prominent at both lung bases (where blood flow greatest)

• bibasilar pulmonary fibrosis:

  Prevalence:

  20 65% on CXR, up to 90% on HRCT

  • fine/coarse reticulations/diffuse interstitial infiltrates

  • subpleural fibrocystic spaces (honeycombing)

• low lung volumes from progressive volume loss

• alveolar changes (secondary to aspiration of refluxed gastric contents with disturbed esophageal motility/mineral oil taken to combat constipation)

• dilated esophagus with air esophagogram (DDx: achalasia, mediastinitis) with increased frequency of aspiration pneumonia

• pleural reaction/effusion distinctly uncommon

HRCT:

• areas of ground-glass attenuation

• poorly defined subpleural nodules

• reticular pattern of attenuation

• traction bronchiectasis

• honeycombing

Cx:

(1) Pulmonary arterial hypertension (6 60%)
(2) Aspiration pneumonia
(3) Increased incidence of lung cancer

• @ Heart: sclerosis of cardiac muscle cor pulmonale

Renal Scleroderma (25%)

Onset:	common within 3 years
Histo:	fibrinoid necrosis of afferent arterioles (also seen in malignant hypertension)

• renal cortical necrosis

P.865




• spotty inhomogeneous nephrogram (constriction + occlusion of arteries)

• concomitant arterial ectasia

Cx:

renal failure (from nephrosclerosis)

Musculoskeletal Scleroderma

• edema of distal portion of extremities

• thickened inelastic waxy skin most prominent about face + extremities

• symmetrical polyarthralgias (50 80%)

• Raynaud phenomenon (may precede other symptoms by months/years)

• atrophy + thickening of skin and musculature (78%)

• @ Fingers

  • sausage digit = edema of digits associated with loss of transverse skin folds + lack of definition of subcutaneous fat

  • tapered fingers = sclerodactyly = atrophy + resorption of soft tissues of fingertips + soft-tissue calcifications

  • acroosteolysis = penciling / autoamputation

    • = resorption of distal phalanges of hand (63%) beginning at volar aspect of terminal tufts with proximal progression

  • calcinosis (25%) = punctate soft-tissue calcifications of fingertips, axilla, ischial tuberosity, forearm, elbow (over pressure area), lower leg, face

  • calcifications around tendons. bursae, within joints

• @ Arthritis

  • stiffness in small joints, occasionally in knee, shoulder, wrist

  • lack of motility, eventually contractures

  • arthritis of interphalangeal joints of hands (25%)

    Location:

    1st CMC, MCP, DIP, PIP

  • central/marginal erosions (50%):

    • resorption of palmar aspect of terminal phalanges (most frequent sign)

    • bony erosions of carpal bones (trapezium), distal radius + ulna, mandible, ribs, lateral aspect of clavicle, humerus, acromion, mandible, cervical spine

  • joint-space narrowing (late)

    DDx:

    rheumatoid, psoriatic, erosive arthritis

  • soft-tissue swelling periarticular osteoporosis

  • NO significant osteoporosis

  • flexion contractures of fingers (from tendon sheath inflammation + fibrosis)

• @ Ribs

  • erosion of superior aspect of ribs

• @ Teeth

  • widening of periodontal membrane

Prolapsed Antral Mucosa

• = prolapse of hypertrophic + inflammatory mucosa of gastric antrum into duodenum resulting in pyloric obstruction

• mushroom-/umbrella-/cauliflower-shaped filling defect at duodenal base

• filling defect varies in size + shape

• redundant gastric rugae can be traced from pyloric antrum through pyloric channel

• gastric hyperperistalsis

Pseudomembranous Colitis

• = CLOSTRIDIUM DIFFICILE DISEASE

• = nosocomial epidemic/endemic acute infectious colitis due to Clostridium difficile toxins

Cause:	unopposed proliferation of gram-positive Clostridium difficile in response to a decrease in normal intestinal flora
Etiologic agent:	toxin A (enterotoxin) + toxin B (cytotoxin) produced by C. difficile

Predisposed:

• complication of antibiotic therapy with tetracycline, penicillin, ampicillin, clindamycin, lincomycin, amoxicillin, chloramphenicol, cephalosporins

• complication of some chemotherapeutic agents: methotrexate, fluorouracil

• following abdominal surgery/renal transplantation/irradiation

• prolonged hypotension/hypoperfusion of bowel

• shock, uremia

• proximal to colonic obstruction

• debilitating diseases: lymphosarcoma, leukemia, advanced HIV infection

• immunosuppressive therapy with actinomycin D

Histo:

pseudomembranes (exudate composed of leukocytes, fibrin, mucin, sloughed necrotic epithelium held in columns by strands of mucus) on a partially denuded colonic edematous mucosa (mucosa generally intact); reactive edema in lamina propria, submucosa, and eventually subserosa

Clinical manifestations of C. difficile infection:

• absence of symptoms (majority)

• antibiotic-associated colitis without pseudomembrane formation

• pseudomembranous colitis

• fulminant colitis

• profuse watery diarrhea, abdominal cramps, tenderness

• fever, fecal blood, leukocytosis

• less common: chronic diarrhea, dehydration, toxic megacolon, hyperpyrexia, leukemoid reaction, hypoalbuminemia with anasarca

Location:

rectum (95%); confined to right + transverse colon (5 27 40%)

• Radiographic abnormalities in 32% with a positive stool toxin assay!

Plain film:

• adynamic ileus pattern = moderate gaseous distension of small bowel + colon:

  • small bowel ileus (20%)

  • colonic ileus (32%)

• nodular haustral thickening (18%):

  • thumbprinting = transverse banding = marked thickening + distortion of haustral folds most prominent in transverse colon

  • diffusely shaggy + irregular surface (confluent pseudomembranes)

• ascites (7%)

BE (CONTRAINDICATED in severe cases):

• pseudoulcerations = barium filling clefts between pseudomembranes

• irregular ragged polypoid contour of colonic wall

P.866




• discrete multiple plaquelike lesions of 2 4 mm in size (DDx: polyposis, nodular form of lymphoma)

N.B.:

risk of colonic perforation in toxic megacolon!

CT (85% sensitive, 48% specific):

• NO colonic abnormality (12 39%)

• colonic wall thickening of 3 32 (mean of 14.7) mm in 61 88%:

  • circumferential/eccentric

  • smooth (44%)/irregular/polypoid (17%)

  • target sign = submucosal edema + mucosal hyperemia (best seen during arterial enhancement)

  DDx:

  wall thickening is greater than in any other colitis except Crohn disease!

• accordion sign (51 70%) = orally administered intraluminal contrast material trapped between distorted thickened closely spaced transverse edematous folds of low attenuation (simulating intramural tracts), TYPICAL but only in severe cases

• colonic dilatation frequent due to transmural inflammation

• homogeneous enhancement due to hyperemia

• usually disproportionately mild pericolonic stranding (42%) relative to marked wall thickening

• ascites in severe cases (15 35%)

• pneumatosis coli portal vein gas in severe cases

Dx:	(1) Stool assay for Clostridium difficile cytotoxin (detects toxin B): cumbersome to perform (2) Enzyme immunoassay test (up to 33% false-negative results): detects toxin A + B (3) Stool culture (95% sensitive): not available for 2 days (4) Pseudomembranes of adherent yellow plaques 2 10 mm in diameter on proctosigmoidoscopy
Cx:	peritonitis, toxic megacolon, perforation
Prognosis:	1.1 3.5% overall mortality; most patients recover within 2 weeks
Rx:	(1) Discontinuation of suspected antibiotic (2) Administration of vancomycin/metronidazole (response within 3 4 days) (3) Attention to fluid and electrolyte balance (4) Life-saving partial colectomy required in <1%
DDx:	acute stage of ulcerative/granulomatous colitis, inflammatory colitis, ischemic colitis, colonic wall hemorrhage, colonic lymphangiectasia, leukemic infiltration, diverticulitis

Pseudomyxoma Peritonei

• = jelly belly = gelatinous ascites

• = slow insidious accumulation of large amounts of intraperitoneal gelatinous material

Etiology:	spillage of mucin from ruptured mucocele with foreign body peritonitis; spread of cystadeno-carcinoma of appendix (male)/ovary (female)
Rarely associated with:	malignancy of colon (<5%), stomach, uterus, pancreas, common bile duct, urachal duct, omphalomesenteric duct

• slowly progressive massive abdominal distension

• recurrent abdominal pain

• thickening of peritoneal + omental surfaces

• omental cake

• posterior fixation of bowel loops + mesentery

• voluminous septated/loculated pseudoascites

• several thin-walled cystic masses of different size throughout abdominal cavity

• scalloped contour of liver + splenic margins

• annular/semicircular calcifications (rare but highly suggestive)

CT:

• intraperitoneal collection of very low attenuation (common)/soft-tissue density (rare)

• may contain enhancing septa calcifications

• discrete hypoattenuating masses (infrequent)

US:

• hypoechoic collection (common)/more solid appearance (rare)

Prognosis:	bowel obstruction with need for multiple surgical debulkings
DDx:	peritoneal metastases, pancreatitis with pseudocysts, pyogenic peritonitis, widespread echinococcal disease, ascites
Prognosis:	50% 5-year survival rate
Rx:	often requires repeated laparotomies for drainage

Radiation Injury

• = obliterative endarteritis with irradiation in excess of 4,000 4,500 rads

Incidence:

5%; increased risk after pelvic surgery

• radiographic changes within field of radiation only

Radiation Gastritis

• Permanent radiographic findings of radiation injury appear 1 month to 2 years after therapy

• gastric ulceration + deformity (pylorus)

• enlargement + effacement of gastric folds

• antral narrowing + rigidity (similar to linitis plastica)

Radiation Enteritis

• Permanent radiographic findings of radiation injury appear >1 2 years following irradiation

Predisposed:

women (cancer of cervix, endometrium, ovary), patients with bladder cancer

• crampy abdominal pain (from intermittent obstruction)

• persistent diarrhea

• occult intestinal hemorrhage

Location:

ileum; concomitant radiation damage to colon/rectum

• irregular nodular thickening of folds with straight transverse course ulcerations

• serrated bowel margin

• thickened bowel wall with luminal narrowing

• multiple strictures + partial mechanical obstruction

• separation of adjacent bowel loops by >2 mm

• shortening of small bowel

• fixation + immobilization of bowel loops with similar radiographic appearance between examinations (from dense desmoplastic response to irradiation)

CT:

• increased attenuation of mesentery

DDx:

Crohn disease, lymphoma, ischemia, hemorrhage

P.867

Radiation Injury of Rectum

• Manifestation of radiation colitis can occur up to 15 years following irradiation

Predisposed:

90% in women (carcinoma of cervix)

• tenesmus, diarrhea, bleeding, constipation

• ridgelike appearance of mucosa (submucosal fibrosis)

• irregularly outlined ulcerations (rare)

CT:

• narrowed partially distensible rectum

• thick homogeneous rectal wall

• target sign = submucosal circumferential lucency

• proliferation of perirectal fat >10 mm

• thickening of perirectal fascia

• halo sign = increase in pararectal fibrosis

Cx:

(1) Obstruction
(2) Colovaginal/coloenteric fistula formation

Retained Gastric Antrum

Cause:	retention of endocrinologically active gastric antrum in continuity with pylorus + duodenum
Pathophysiology:	bathing of antrum in alkaline duodenal juice stimulates secretion of gastrin
Associated with:	gastric ulcers in 30 50%

• duodenogastric reflux of barium through pylorus (diagnostic)

• giant marginal ulcer/several marginal ulcers usually on jejunal side of anastomosis (large false-negative + false-positive rates; correct-positive rate of 28 60%)

• large amount of secretions

• edematous mucosa of jejunal anastomotic segment

• lacy/cobweblike small bowel pattern (hypersecretion)

Cx:

gastrojejunocolic fistula

Retractile Mesenteritis

• = CHRONIC FIBROSING MESENTERITIS = CHRONIC SUBPERITONEAL SCLEROSIS = MESENTERIC PANNICULITIS = LIPOSCLEROTIC MESENTERITIS

  • = LIPOGRANULOMA OF THE MESENTERY = MESENTERIC

  • LIPODYSTROPHY = ISOLATED LIPODYSTROPHY

  • = RETROPERITONEAL XANTHOGRANULOMA

  • = MESENTERIC WEBER-CHRISTIAN DISEASE

• = rare benign disorder of unknown etiology characterized by fibrofatty thickening of small bowel mesentery

Etiology:	trauma, previous surgery, ischemia
Age:	most common in 6th decade; M:F = 2 3:1

Associated with:

• Gardner syndrome, familial polyposis

• Fibrosing mediastinitis, retroperitoneal fibrosis

• Lymphoma, lymphosarcoma (in 15%)

• Carcinoid tumor

• Metastatic gastric/colonic carcinoma

• Whipple lipodystrophy

• Weber-Christian disease

Location:	root of mesentery extending toward mesenteric border of bowel
Site:	small bowel mesentery; occasionally mesocolon, sigmoid mesentery, omentum, retroperitoneum

Plain film:

• soft-tissue mass with calcifications

• thumbprinting (from vascular congestion)

UGI:

• compression/distortion of duodenum near ligament of Treitz

• separation of small bowel loops with fixation, kinking, and angulation

CT:

• mass of fat density interspersed with soft-tissue density (fibrous tissue) + calcifications

• mesenteric thickening with fine stellate pattern extending to bowel border

• retraction of small bowel loops

• single mesenteric soft-tissue mass (fibroma)

• multiple nodules throughout mesentery (fibromatosis)

Dx:	supported by absence of pancreatitis/inflammatory bowel disease
Prognosis:	usually benign course with spontaneous resolution
Rx:	steroids
DDx:	pseudomyxoma peritonei (from metastatic gastric/colonic adenocarcinoma); carcinoid/desmoid tumor; mesenteric lymphoma, lymphosarcoma; liposarcoma of mesentery; pyogenic peritonitis

Mesenteric Lipodystrophy (1st stage)

• = degeneration of mesenteric fat

Path:	diffuse mesenteric thickening (42%); solitary (32%)/multiple (26%) discrete mesenteric masses
Histo:	sheets of foamy macrophages with scattered lymphocytic infiltration replacing mesenteric fat

• asymptomatic

• chylous ascites

Prognosis:

spontaneous recovery

Mesenteric Panniculitis (2nd stage)

• = inflammatory changes in mesenteric adipose tissue

Path:	diffuse mesenteric thickening with puckering of mesenteric surface due to desmoplastic reaction; adherent mass(es) in root of mesentery; fat necrosis
Histo:	infiltrate of plasma cells, foreign body giant cells, foamy macrophages

• crampy abdominal pain; bowel disturbances

• nausea + vomiting; malaise; mild weight loss

• poorly defined mass (50%)/abdominal fullness

• low-grade fever

Retractile Mesenteritis (3rd stage)

• = fibrosis of adipose tissue

Histo:

collagen deposition, fibrosis, inflammation; calcifications

• intestinal obstruction

Schatzki Ring

• = LOWER ESOPHAGEAL MUCOSAL RING

• = constant lower esophageal ring (mucosal thickening) presumed to result from reflux esophagitis = thin annular peptic stricture

Incidence:	6 14% of population; old age > young age; M > F
Histo:	usually squamous epithelium on upper surface + columnar epithelium on undersurface; may be covered totally by squamous epithelium or columnar epithelium

P.868

• asymptomatic (if ring >20 mm)

• dysphagia (if ring <12 mm)

Location:

near the squamocolumnar junction; in region of B ring at inferior margin of lower esophageal sphincter

• permanently present nondistensible transverse ring with constant shape + size (range of 3 18 mm)

• 2 4-mm-thick shelflike projection into lumen with smooth symmetric margins

• visible only with adequate distension of esophagogastric region and when located above the esophageal hiatus of the diaphragm

• best demonstrated in prone position during arrested deep inspiration with Valsalva maneuver while solid barium column passes through esophagogastric region

• short esophagus + intrahiatal/intrathoracic gastric segment

  • = sliding hiatal hernia if Schatzki ring located 1 2 cm above diaphragmatic hiatus

Prognosis:	decrease in caliber over 5 years (in 25 33%)
Cx:	impaction of food bolus (associated with severe chest pain)
Rx:	(1) Proper mastication of food (2) Endoscopic rupture (3) Esophageal dilatation (radiographically often lack of caliber change after successful dilatation)
DDx:	annular peptic stricture (usually thicker, asymmetric, irregular surface, associated with thickened esophageal folds, serration of esophageal margins)

Schwannoma

• = rare neurogenic tumor

Incidence:	4% of all benign gastric tumors are neurogenic tumors
Location:	stomach

• discrete submucosal mass

Cx:

(1) Ulceration (pressure necrosis of overlying mucosa)
(2) Central necrosis (after outgrowing its blood supply)

Small Bowel Volvulus

• = rare life-threatening surgical emergency

Cause:

adhesive bands, internal hernia, external hernia

Pathophysiology:

• closed-loop obstruction bacterial overgrowth accelerated fluid sequestration + gas production increased intraluminal pressure + dilatation compromise of vascular supply to intestinal wall hemorrhagic infarction necrosis perforation

• poor/absent enhancement of bowel wall

• spoke wheel sign = radial peripheral distribution of distended fluid-filled small-bowel loops around central engorged thickened mesenteric vessels (75%)

• two collapsed adjacent bowel loops = site of constriction (35%)

• U-shaped configuration of distended fluid-filled small-bowel loops = radial arrangement of incarcerated fluid-filled dilated loop at periphery of tightly twisted mesentery (30%)

• triangular sign = fusiform tapering of collapsed loop at site of constriction on longitudinal section through loop (15%)

• whirl sign = swirling appearance of twisted mesentery (10%)

Cx:	(1) bowel ischemia in 46% due to closed-loop obstruction + torsion of mesenteric vessels (2) bowel necrosis
Mortality:	9%

Small Left Colon Syndrome

Cause:	transient functional colonic obstruction due to immaturity of mesenteric plexus
Age:	newborn infant
Associated with:	maternal diabetes mellitus (most common), maternal substance abuse; NOT related to cystic fibrosis

• colonic caliber becomes abruptly diminutive distal to splenic flexure

• bowel dilatation proximal to splenic flexure

• meconium plug (as a result and not the cause of obstruction)

Prognosis:

gradual resolution of functional immaturity over days to weeks

Solitary Rectal Ulcer Syndrome

• = MUCOSAL PROLAPSE SYNDROME

Related disorders with common pathogenesis:

• hamartomatous inverted polyp, colitis cystica profunda

Cause:	prolapse of anterior rectal wall resulting in mucosal ischemia due to traumatization of rectal mucosa by anal sphincter during defecation (rectal straining/prolapse)
Age:	young patients (especially women)
Path:	small/large, single/multiple shallow ulcers; 25% broad-based, 18% patchy granular/velvety hyperemic mucosa; rectal stenosis through confluent circumferential lesion
Histo:	obliteration of lamina propria mucosae by fibromuscular proliferation of muscularis mucosae, streaming of fibroblasts + muscle fibers between crypts, misplaced mucosal glands deep to muscularis mucosae; diffuse increase in mucosal collagen

• chronic rectal bleeding

• passage of mucus

• disordered defecation

• tenesmus

BE:

• ulcer (ulcerative type) on anterior rectal wall

• polypoid lesion/nodules (polypoid type)

• flat granular mucosa (flat type)

• thickened valves of Houston without ulcer

• stricture

Evacuation proctography:

• failure of anorectal angle to open while straining

• excessive perineal descent

Prognosis:

• Little change over time

• Considerable change in appearance of lesion

• Transfusions necessitated by massive blood loss

Dx:	rectal biopsy
DDx:	invasive rectal carcinoma, Crohn disease

Sprue

• = classic disease of malabsorption

P.869

Path:

villous atrophy (truncation) + elongation of crypts of Lieberk hn (crypt hyperplasia) + round cell infiltration of lamina propria and epithelium (plasma cells, mast cells, lymphocytes, eosinophils)

• severe diarrhea, steatorrhea (CLASSIC but found only in minority of patients); flatulence

• crampy abdominal pain (from intussusception)

• lassitude, fatigue, weight loss, failure to thrive

• recurrent oral aphthous ulcers, dental enamel defects (10 40%)

• peripheral neuropathy, ataxia, dementia, seizures

• bleeding diathesis

• infertility

• idiopathic osteopenia with bone pain

• dermatitis herpetiformis (= pruritic bullous skin rash)

• anemia from iron/folate/vitamin B¹²deficiency

• low serum levels of cholesterol, calcium, albumin

• elevated alkaline phosphatase + liver enzymes

• prolonged prothrombin time

• Serologic testing for antibodies to gliadin + endomysium in screening + monitoring compliance

Location:

patchy involvement of duodenum + jejunum > remainder of small bowel

Small bowel follow-through:

• small bowel dilatation is HALLMARK in untreated celiac disease (70 95%), best seen in mid + distal jejunum (due to intestinal hypomotility); degree of dilatation related to severity of disease

• hypersecretion-related artifacts:

  • air-fluid levels in small bowel (rare)

  • segmentation = breakup of normal continual column of barium creating large masses of barium in dilated segments separated by stringlike strands from adjacent clumps due to excessive fluid; best seen on delayed films

  • flocculation = coarse granular appearance of small clumps of disintegrated barium due to excess fluid best seen at periphery of intestinal segment; occurs especially with steatorrhea

  • fragmentation = scattering = faint irregular stippling of residual barium resembling snowflakes associated with segmentation due to excessive fluid

• moulage sign (50%) = smooth contour with effaced featureless folds resembling tubular wax mold (due to atrophy of the folds of Kerckring); CHARACTERISTIC of sprue if seen in duodenum + jejunum

• long/normal/short transit time

• nonpropulsive peristalsis (flaccid + poorly contracting loops)

• normal/thickened/effaced mucosal folds (depending on degree of hypoproteinemia)

• colonlike haustrations in well-filled jejunum (secondary to spasm + cicatrization from transverse ulcers)

• jejunization of ileal loops (= adaptive response to decreased jejunal mucosal surface) = SPECIFIC

• transient nonobstructive intussusception (20%) without anatomic lead point

• bubbly bulb = peptic duodenitis = mucosal inflammation, gastric metaplasia, Brunner gland hyperplasia

Enteroclysis:

• decreased number of folds in proximal jejunum ( 3 folds per inch)

• increased number of folds in distal ileum (>5 folds per inch)

• tubular featureless lumen

• mosaic pattern = 1 2-mm polygonal islands of mucosa surrounded by barium-filled distinct grooves (10%)

CT:

• small bowel dilatation + increased fluid content mucosal fold thickening

• mild to moderate lymphadenopathy in mesentery/retroperitoneum (up to 12%)

US:

• moderately dilated fluid-filled small intestine

• thickening of small bowel wall

• hyperperistalsis (82%)

• dilated superior mesenteric artery + portal vein

• liver steatosis (metabolic derangement from malabsorption)

• mesenteric + retroperitoneal lymphadenopathy (12%)

• slight ascites (76%)

Dx:	(1) Clinical presentation (2) Jejunal/duodenal biopsy with typical histopathologic features (3) Improvement of small bowel abnormalities after a few months of a gluten-free diet
Cause for relapse:	hidden dietary gluten, diabetes, bacterial overgrowth, intestinal ulceration, development of lymphoma

Cx:

• Ulcerative jejunoileitis

  • = multiple chronic benign ulcers (sausage appearance of small bowel) with hemorrhage, perforation + obstruction

  Age:	5th 6th decade
  Location:	jejunum > ileum > colon

  • response to gluten-free diet ceases

  Prognosis:	frequently fatal
  Rx:	small bowel resection

• Hyposplenism (30 50%)

  • small atrophic spleen

• Cavitating mesenteric lymph node syndrome

  Path:

  multiple pseudocystic lymph nodes containing chylous fluid (thin milky fluid/thick creamy material) + thin peripheral rim of fibrous material and scant elements of atrophic lymph node structures

  • refractory weight loss, fatigue, diarrhea

  • target cells + Howell-Jolly bodies in peripheral blood smear (signs of hyposplenism)

  Location:

  confined to jejunoileal mesentery

  • multiple 2 7-cm large lymph nodes with a central cavity of low attenuation fat-fluid levels

  • splenic atrophy

  • villous atrophy of small intestinal mucosa

  Prognosis:

  usually fatal disorder

• Malignant tumors (up to 14%)

  • lymphoma (in 8%):

    Type:	enteropathy-associated T-cell lymphoma (85 90%) + extraintestinal lymphoma (mostly Hodgkin lymphoma)
    Peak prevalence:	7th decade

    • enlarged nodular folds, ulcers, extrinsic mass effect

  P.870

  
  

  • adenocarcinoma of small bowel (7%), rectum, stomach

  • squamous cell carcinoma of esophagus (in 4%) during 6th 7th decade

  • malignancies of oropharynx, ovaries, testicles, thyroid, breast, lungs

• Generalized lymphadenopathy with lymphocytosis (mimicking lymphoma)

• Sigmoid volvulus (rare)

DDx:

• Esophageal hypoperistalsis: scleroderma, idiopathic pseudoobstruction

• Gastric abnormalities: Zollinger-Ellison syndrome, chronic granulomatous disease, eosinophilic enteritis, amyloidosis, malignancy

• Tiny nodular defects on thickened folds: Whipple disease, intestinal lymphangiectasia, Waldenstr m macroglobulinemia

• Small 1 3-mm nodules: lymphoid hyperplasia associated with giardiasis and immunoglobulin deficiency disease, diffuse lymphoma

• Small nodules of varying sizes: systemic mastocytosis, amyloidosis, eosinophilic enteritis, Cronkhite-Canada syndrome

• Bowel wall narrowing, kinking, scarring, ulceration: regional enteritis, bacterial/parasitic infection, carcinoid, vasculitis, ischemia, irradiation

Celiac Disease

• = CELIAC SPRUE = NONTROPICAL SPRUE = GLUTEN-SENSITIVE ENTEROPATHY

Cause:	genetically based immunologic intolerance to ingested grain glutens causing inflammation + damage of small intestinal villi; detected in 15% of 1st-degree relatives
Irritating agent:	gliadin polypeptides in wheat, rye, barley, oats
Countries:	North America, Europe, Australia, India, Pakistan, Middle East, Cuba
Incidence:	1:200 to 1:500
Age:	childhood by age 2 years; 30 40 years with M < F; 40 60 years with M > F
Rx:	gluten-free diet: corn, rice, tapioca, soya, millet, vitamin supplements

Tropical Sprue

Etiology:	infectious agent cured with antibiotics; geographic distribution (India, Far East, Puerto Rico)
Age:	any age group

• glossitis

• hepatosplenomegaly

• macrocytic anemia + leukopenia

Prognosis:	spontaneous resolution after months/years
Rx:	responds well to folic acid + broad-spectrum antibiotics

Strongyloidiasis

Organism:	helminthic parasite Strongyloides stercoralis (2.2 mm long, 50 m in diameter); capable of reproducing within human host
Prevalence:	100 million cases globally; 0.4 4% in USA
Country:	tropical + subtropical regions, parts of Europe, southeastern USA (eastern Kentucky, rural Tennessee), Puerto Rico
Primary host:	humans
Infection:	filiform larva enters body through skin/mucous membranes (from contaminated soil)
Cycle:	filariform larva penetrates skin and passes from subcutaneous/submucosal sites via lymphatic + venous circulation to lung; larva breaks into alveolar spaces and ascends bronchi + trachea; larva swallowed; settles in duodenum + upper jejunum (lives in tunnels between enterocytes); larva matures into parasitic adult female worm; worm deposits eggs into the intestinal lumen; ova hatch immediately into nonmigratory rhabditiform larvae, which are excreted in feces Autoinfection (endogenous reinfection) rhabditiform larva may remain in intestines long enough to metamorphose into infective filariform larva, which penetrates intestinal mucosa/perianal skin and reenters venous system repeating life cycle in same host
Path:	edema + inflammation of intestinal wall secondary to invasion by larvae; flattening of villi; ova in mucosal crypts
Histo:	intact larvae with Gomori methenamine silver stain

• asymptomatic for many years (in majority)

• midepigastric pain mimicking peptic ulcer disease

• weight loss

• severe malnutrition (malabsorption, steatorrhea)

• larva currens = recurrent allergic pruritic cutaneous skin reaction at site of larval penetration within 24 hours in area of buttocks + upper thighs in patients with autoinfection

• worms, larvae, eggs in stool

• blood eosinophilia (extremely common)

• elevated levels of immunoglobulin E

• paralytic ileus (due to massive intestinal infestation):

  • mild to moderate dilatation of proximal 2/3 of duodenum + jejunum

  • edematous irregular mucosal folds

• ulcerations

• stricture of 3rd + 4th part of duodenum

  • rigid pipestem appearance + irregular narrowing of duodenum (in advanced cases)

Rx:	thiabendazole (90% efficacy rate)
Prognosis:	high mortality in undernourished patients

Strongyloides Hyperinfection Syndrome

• = widespread dissemination + extensive tissue invasion in immunocompromised host with malignancy, autoimmune disease, malnutrition

• gram-negative bacteremia, septicemia (due to spillage of gut organisms into bloodstream at time of larval penetration of intestinal wall)

• crampy abdominal pain, nausea, diarrhea

• persistent vomiting, hematemesis

• thickened colonic wall (due to florid transmural granulomatous inflammatory colitis caused by invasive larvae)

P.871




• @ Heart, skeletal muscle, lymph nodes, liver

  • endocarditis, peritonitis

• @ CNS

  • meningitis due to larvae in pia arachnoid

  • global ischemia, atrophy, microinfarcts (from capillary obstruction)

• @ Lung

Histo:

foreign body reaction resulting in inflammatory pneumonitis + pulmonary hemorrhage

• dyspnea, cough, sputum production, wheezing

• hemoptysis

• fine miliary nodules

• diffuse reticulonodular interstitial opacities

• fleeting bilateral patchy alveolar/segmental/lobar opacities (with heavy infestation)

• adult ARDS may develop

Dx:

filariform larvae in stool (single stool sample in 70% negative), sputum samples/bronchial washings/bronchial/lung biopsy specimens, CNS samples

Superior Mesenteric Artery Syndrome

• = VASCULAR COMPRESSION OF DUODENUM = WILKIE SYNDROME = CHRONIC DUODENAL ILEUS = BODY CAST SYNDROME

• = vascular compression of 3rd portion of duodenum within aortomesenteric compartment; probably representing a functional reflex dilatation

Pathophysiology:	narrowing of angle between SMA + aorta to 10 22 (normal 45 65 )
Cause:	congenital, weight loss, visceroptosis due to loss of abdominal muscle tone (as in pregnancy), asthenic build, exaggerated lumbar lordosis, prolonged bed rest in supine position (body cast, whole-body burns, surgery)

• repetitive vomiting

• abdominal cramping

• megaduodenum = pronounced dilatation of 1st + 2nd portion of duodenum + frequently stomach, best seen in supine position

• vertical linear compression defect in transverse portion of duodenum overlying spine

• abrupt change in caliber distal to compression defect

• relief of compression by postural change into prone knee elbow position

Tailgut Cyst

• = RETRORECTAL CYSTIC HAMARTOMA

Cause:	incomplete regression of embryonic tailgut (= the portion distal to future anus)
Average age:	35 years; M < F
Histo:	several types of epithelia + elements of intestinal epithelium, smooth muscle within cyst wall

• asymptomatic/perirectal pain, rectal bleeding, urinary frequency

Location:

retrorectal/presacral space extension into ischiorectal fossa

• thin-walled multicystic/unilocular cyst adhering to sacrum/rectum

• clear fluid/mucoid fluid with internal echoes

Cx:

(1) Repeated perirectal abscesses, recurring anorectal fistula (2) Degeneration into mucinous adenocarcinoma

Toxic Megacolon

• = acute transmural fulminant colitis with neurogenic loss of motor tone + rapid development of extensive colonic dilatation >5.5 cm in transverse colon (damage to entire colonic wall + neuromuscular degeneration)

• Etiology:

  • Ulcerative colitis (most common)

  • Crohn disease

  • Amebiasis, salmonellosis

  • Pseudomembranous colitis

  • Ischemic colitis

Histo:

widespread sloughing of mucosa + thinning of frequently necrotic muscle layers

• systemic toxicity

• profuse bloody diarrhea

• colonic ileus with marked dilatation of transverse colon

• few air-fluid levels

• increasing caliber of colon on serial radiographs without redundancy

• loss of normal colonic haustra + interhaustral folds

• coarsely irregular mucosal surface

• pseudopolyposis = mucosal islands in denuded ulcerated colonic wall

• pneumatosis coli pneumoperitoneum

CT:

• distended colon filled with large amounts of fluid + air

• distorted haustral pattern

• irregular nodular contour of thin wall

• intramural air/small collections

BE:	CONTRAINDICATED due to risk of perforation
Prognosis:	20% mortality

Tuberculosis

• Rarely encountered in Western Hemisphere, increased incidence in AIDS; usually associated with pulmonary tuberculosis (in 6 38%)

• Etiology:

  • Ingestion of tuberculous sputum

  • Hematogenous spread from tuberculous focus in lung to submucosal lymph nodes

    • Radiographic evidence of pulmonary TB in <50%

  • Primary infection by cow milk (Mycobacterium bovis)

• Path:

  • ulcerative form (most frequent): ulcers with their long axis perpendicular to axis of intestine, undermining + pseudopolyps

  • hypertrophic form: thickening of bowel wall (transmural granulomatous process)

Organism:	M. tuberculosis, M. bovis, M. avium-intracellulare
Age:	20 40 years

• weight loss, abdominal pain (80 90%)

• nausea, vomiting

• tuberculin skin test negative in most patients with primary intestinal TB

Location:

ileocecal area > ascending colon > jejunum > appendix > duodenum > stomach > sigmoid > rectum

P.872

• @ Tuberculous peritonitis (in 1/3)

  • Most common presentation associated with widespread abdominal disease!

  Cause:

  hematogenous spread/rupture of mesenteric node

  • Types:

    • wet type (most common) = exudative ascites with high protein contents + leukocytes

      • large amount of freely distributed/loculated viscous fluid

      • high-density ascites of 20 45 HU (due to high protein + cellular content)

    • dry/plastic type = caseous adenopathy + adhesions

      • caseous nodules, fibrous peritoneal reaction, dense adhesions

    • fibrotic-fixed type = omental cakelike mass with separation + fixation of bowel loops

      • irregular masses of soft-tissue density in omentum + mesentery (common)

      • matted loops of bowel and mesentery

      • loculated ascites (occasionally)

  • CT:

    • enlarged lymph nodes (90%) with low-density centers in 40% (due to caseous necrosis)

      Location:

      peripancreatic, mesenteric, omental, retroperitoneal Lnn

    • infiltration of mesentery

  Cx:

  small bowel obstruction (adhesions from serosal tubercles)

• @ Ileocecal area (80 90%)

  • Most commonly affected bowel segment!

  Cause:

  relative stagnation of intestinal contents + abundance of lymphoid tissue (Peyer patches)

  • Stierlin sign = rapid emptying (hypermotility) of narrowed terminal ileum (spasm) into shortened rigid obliterated cecum on BE

  • thickened ileocecal valve (mass effect)

  • Fleischner sign = inverted umbrella defect = wide gaping patulous ileocecal valve associated with narrowing of the immediately adjacent terminal ileum

  • deep fissures + large shallow linear/stellate ulcers with CHARACTERISTIC elevated margins following the orientation of lymphoid follicles (ie, longitudinal in terminal ileum and transverse in colon)

  • sinus tracts (rare)/enterocutaneous fistulas/perforation

  • symmetric annular napkin ring stenoses

  • CT:

    • circumferential wall thickening of cecum + terminal ileum

    • asymmetric thickening of ileocecal valve + medial wall of cecum

    • exophytic extension engulfing terminal ileum

    • adjacent massive mesenteric lymphadenopathy with central areas of low attenuation

  DDx:

  Crohn disease, amebiasis, cecal carcinoma

• @ Colon

  Site:

  segmental colonic involvement, esp. on right side

  • rigid contracted cone-shaped cecum (spasm/transmural fibrosis)

  • spiculations + wall thickening

  • diffuse ulcerating colitis + pseudopolyps

  • short hourglass strictures

  • shortened amputated cecum secondary to retraction of cecum out of the iliac fossa (due to fibrosis of mesocolon)

  DDx:

  ulcerative colitis, Crohn disease, amebiasis (spares terminal ileum), colitis of bacillary dysentery, ischemic colitis, pseudomembranous colitis

• @ Gastroduodenal

  Site:

  simultaneous involvement of pylorus + duodenum

  • stenotic pylorus with gastric outlet obstruction

  • narrowed antrum (linitis plastica appearance)

  • antral fistula

  • multiple large and deep ulcerations on lesser curvature

  • thickened duodenal folds with irregular contour/dilatation

  DDx:

  carcinoma, lymphoma, syphilis

• @ Esophagus

  • Least common GI tract manifestation

  Cause:

  secondary involvement from adjacent tuberculous lymphadenitis/primary TB

  • deep ulceration

  • stricture

  • mass

  • intramural dissection/fistula formation = sinus tract formation

Turcot Syndrome

• = autosomal recessive disease with

  • colonic polyposis

  • CNS tumors (especially supratentorial glioblastoma, occasionally medulloblastoma)

Age:	symptomatic during 2nd decade
Histo:	adenomatous polyps

• diarrhea

• seizures

• multiple 1 30-mm polyps in colon + rectum

Cx:	malignant transformation of colonic polyps in 100%
Prognosis:	death from brain tumor in 2nd + 3rd decade

Typhlitis

• = ILEOCECAL SYNDROME = NEUTROPENIC COLITIS

• = acute inflammation of cecum, appendix, and occasionally terminal ileum; initially described in children with leukemia + severe neutropenia;

  • [typhlos, Greek = blind sac = cecum]

Cause:	leukemic/lymphomatous infiltrate, ischemia, focal pseudomembranous colitis, infection (CMV)
Histo:	edema + ulceration of entire bowel wall; transmural necrosis with perforation possible
Organism:	CMV, Pseudomonas, Candida, Klebsiella, E. coli, B. fragilis, Enterobacter
Predisposed:	common in childhood leukemia, aplastic anemia, lymphoma, immunosuppressive therapy (eg, renal transplant), cyclic neutropenia, myelodysplastic syndrome, clinical AIDS

• abdominal pain, may be localized to RLQ

• watery/bloody diarrhea

• fullness/palpable mass in RLQ

• fever, neutropenia

• hematochezia/occult blood

P.873

Location:

cecum + ascending colon, appendix + distal ileum may become secondarily involved

• fluid-filled masslike density in RLQ

• distension of nearby small bowel loops

• thumbprinting of ascending colon

• circumferential thickening of cecal wall >4 mm

• occasionally pneumatosis

• CT (preferable examination due to risk of perforation):

  • circumferential wall thickening (>1 3 mm) of cecum terminal ileum

  • decreased bowel wall attenuation (edema)

  • increased attenuation of adjacent fat + thickening of fascial planes (pericolonic inflammation)

  • pericolonic fluid + intramural pneumatosis

Cx:	Perforation (BE is a risky procedure) Abscess formation
Rx:	Early aggressive medical support (high doses of antibiotics + IV fluids), bowel rest, total parenteral nutrition, electrolyte replacement prior to development of transmural necrosis Surgery with uncontrollable GI bleeding, obstruction, abscess, transmural necrosis, free perforation, uncontrollable sepsis
DDx:	Leukemic/lymphomatous deposits (more eccentric thickening) Appendicitis with periappendicular abscess (normal cecal wall thickness) Diverticulitis Inflammatory bowel disease

DDx between Crohn Disease and Ulcerative Colitis
	Crohn Disease	Ulcerative Colitis
mnemonic:	LUCIFER M
Location	right side	left side
Ulcers	deep	shallow
Contraction	no	yes
Ileocecal valve	thickened	gaping
Fistulae	yes	no
Eccentricity	yes	no
Rate of carcinoma	slight increase	marked increase
Megacolon	unusual	yes

Ulcerative Colitis

• = common idiopathic inflammatory bowel disease with continuous concentric + symmetric colonic involvement

Etiology:	hypersensitivity/autoimmune disease
Prevalence:	50 80:100,000 In high incidence areas of North America, Northern Europe, Australia
Path:	predominantly mucosal + submucosal disease with exudate + edema + crypt abscesses (HALLMARK) resulting in shallow ulceration
Age peak:	20 40 years + 60 70 years; M:F = 1:1

• alternating periods of remission + exacerbation

• bloody diarrhea

• electrolyte depletion, fever, systemic toxicity

• abdominal cramps

Extracolonic manifestations:

• iritis, erythema nodosum, pyoderma gangrenosum

• pericholangitis, chronic active hepatitis, primary sclerosing cholangitis, fatty liver

• spondylitis, peripheral arthritis, coincidental rheumatoid arthritis (10 20%)

• thrombotic complications

  Location:

  begins in rectum with proximal progression (rectum spared in 4%); relatively uniform symmetric involvement of bowel

  • rectosigmoid in 95% (diagnosed by rectal biopsy); continuous circumferential involvement often limited to left side of colon

  • colitis extending proximally to splenic flexure = universal colitis

  • terminal ileum in 10 25% ( backwash ileitis )

Plain film:

• hyperplastic mucosa, polypoid mucosa, deep ulcers

• diffuse dilatation with loss of haustral markings

• toxic megacolon

• free intraperitoneal gas

• complete absence of fecal residue (due to inflammation)

BE:

• acute stage

  • narrowing + incomplete filling (spasm + irritability)

  • fine mucosal granularity = stippling of barium coat (from diffuse mucosal edema + hyperemia + superficial erosions)

  • spicules + serrated bowel margins (tiny superficial ulcers)

  • collar button ulcers (= undermining of ulcers)

  • double-tracking = longitudinal submucosal ulceration over several cm

  • hazy/fuzzy quality of bowel contour (excessive secretions)

  • thumbprinting = symmetric thickening of colonic folds

  • pseudopolyps = scattered islands of edematous mucosa + reepithelialized granulation tissue within areas of denuded mucosa

  • widening of presacral space

  • obliterated rectal folds = valves of Houston (43%)

• subacute stage

  • distorted irregular haustra

  • inflammatory polyps = sessile frondlike/rarely pedunculated lesions (= localized mucosal inflammation resulting in polypoid protuberance)

  • coarse granular mucosa (= mucosal replacement by granulation tissue)

• chronic stage

  • shortening of colon (= reversible spasm of longitudinal muscle) with depression of flexures

  • leadpipe colon = rigidity + symmetric narrowing of lumen

  • widening of haustral clefts/complete loss of haustrations (DDx: cathartic colon)

  • burnt-out colon = fairly distensible colon without haustral markings + without mucosal pattern

  • hazy/fuzzy quality of bowel contour (excessive secretions)

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  • postinflammatory polyps (12 19%) = small sessile nodules/long wormlike branching + bridging outgrowths (= filiform polyposis)

  • backwash ileitis (5 30%) involving 4 25 cm of terminal ileum with patulous ileocecal valve + absent peristalsis + granularity

CT:

• wall thickening <10 mm

Cx:

• Toxic megacolon perforation in 5 10%

  • (DDx: granulomatous/ischemic/amebic colitis)

  • Most common cause of death in ulcerative colitis!

• Colonic adenocarcinoma (3 5%):

  • risk starts after 8 10 years of onset of disease; risk progresses at 0.5%/year for 10 20 years + at 0.9%/year thereafter; higher risk with pancolitis + onset of disease in <15 years of age

  Usually associated with:	total colitis
  Location:	rectosigmoid > descending colon, distal transverse colon

  • narrowed segment of 2 6 cm in length with eccentric lumen + irregular contour + flattened rigid tapered margins = scirrhous carcinoma

  • annular/polypoid carcinoma

  Prognosis:

  synchronous lesions in 35%

• Colonic strictures (10%)

  • smooth contour with fusiform pliable tapering margins, usually short + single stricture; commonly in sigmoid/rectum/transverse colon; usually after minimum of 5 years of disease; rarely cause for obstruction (DDx: colonic carcinoma)

• Perforation

DDx:

1. Familial polyposis (no inflammatory changes)
2. Cathartic colon (more extensive in right colon)

Villous Adenoma

Villous Adenoma of Colon

Incidence:	7% of all colonic tumors
Age:	presentation late in life; M = F
Location:	rectum + sigmoid (75%), cecum, ileocecal valve; 2% of all tumors in rectum + colon
Associated with:	other GI tumors (25%)

• sensation of incomplete evacuation

• rectal bleeding

• excretion of copious amounts of thick mucus

• fatigability, weakness

• diarrhea + electrolyte depletion syndrome in 4% (dehydration, hypokalemia, hyponatremia)

• may completely encircle the colon

• broad-based sessile bulky tumor often >20 mm in diameter:

  • innumerable papillary mucosal projections ( villous fronds ) with reticular/granular surface pattern (if villous elements constitute >75% of tumor, diagnosis can be made on BE):

  • spongelike corrugated appearance (barium within interstices)

  • striated brushlike surface

• soft pliable tumor with change in shape:

  • apparent decrease in size on postevacuation films

• CT:

  • heterogeneous low attenuation on CT (due to capacious mucin becoming trapped within papillary projections + crevices)

Prognosis:	higher malignant potential than tubular adenoma
Cx:	malignant transformation/invasion (in 36%) related to size of tumor <5 cm (9%); >5 cm (55%); >10 cm (100%)

Villous Adenoma of Duodenum

• More common in colon + rectum; fewer than 50 cases in world literature

• sessile, soft nonobstructive mass

• lace / soap bubble pattern

• preservation of peristaltic activity + bowel distensibility

Waldenstr m Macroglobulinemia

• = low-grade lymphoid malignancy composed of mature plasmacytoid lymphocytes with production of abnormal monoclonal IgM protein

Incidence:	0.53/100,000 annually; frequency 10 15% that of multiple myeloma
Histo:	macroglobulin proteinaceous hyaline material fills lacteals in lamina propria of small bowel villi with secondary lymphatic distension + edema
Mean age:	63 years; M > F

• fatigue, weight loss

• diarrhea, steatorrhea, malabsorption

• anemia, bleeding diathesis

• IgM elevation

• hyperviscosity syndrome (20%) = bleeding, visual changes, neurologic abnormalities

• @ Small bowel (rarely involved)

  • small bowel dilatation

  • uniform diffuse thickening of valvulae conniventes with spikelike configuration (jejunum + proximal ileum)

  • granular surface of punctate filling defects (distended villi)

• @ Bone marrow involvement (91 98%)

  • (a) diffuse replacement of bone marrow (56%)

  • (b) variegated replacement of bone marrow (35%)

  • compression fractures of spine (48%)

  • diffuse demineralization of spine

  • lytic lesions on bone surveys (in up to 20%)

  • MR (pre- and post-contrast T1WI preferred):

    • marrow iso-/hypointense to muscle on T1WI

    • enhancement of abnormal marrow on T1WI

• @ Lymph nodes

  • lymphadenopathy (43%)

• @ Liver & spleen

  • hepatosplenomegaly

Dx:	characteristic M-spike in serum/urine electrophoresis abnormal lymphplasmacytoid cells in bone marrow/lymph nodes
DDx:	multiple myeloma (lymphadenopathy rare, lytic lesions in 31%)

Whipple Disease

• [George Whipple (1878 1976), pathologist in Rochester, USA]

• = INTESTINAL LIPODYSTROPHY

• = sporadically occurring chronic multisystem disease

P.875

Etiology:	thought to be caused by infection with a gram-positive bacterium (Tropheryma whippelii) closely related to actinobacteria
Histo:	PAS-positive material (periodic acid Schiff) = glycoprotein (from bacterial cell wall) within foamy macrophages in the submucosa of the jejunum + fat deposits within intestinal submucosa and lymph nodes causing lymphatic obstruction + dilatation
Age:	4th 6th decade (mean age of onset, 50 years); M:F = 8:1; Caucasians

• recurrent and migratory arthralgias/nondeforming arthritis (65 95%); arthritis may precede Whipple disease in 10% up to 10 years

• malabsorption, steatorrhea, abdominal pain

• weight loss, low-grade fever

• polyserositis

• generalized peripheral lymphadenopathy (50%)

• hyperpigmentation of skin similar to Addison disease

• pale shaggy yellow plaques/erosions in postbulbar duodenum on endoscopy

  Organ involvement:

  liver, intestines, joints, heart, lung, CNS, eyes, skin (virtually every organ system)

• moderate thickening of jejunal + duodenal folds (from mucosal + submucosal infiltration by PAS-positive macrophages combined with lymphatic obstruction)

• micronodularity (= swollen villi) and wild mucosal pattern

• hypersecretion, segmentation, fragmentation (occasionally if accompanied by hyperproteinemia)

• NO/minimal dilatation of small bowel

• NO rigidity of folds, NO ulcerations

• normal transit time (approximately 3 hours)

• hepatosplenomegaly

• CT:

  • bulky 3 4-cm large low-density lymph nodes in mesenteric root + retroperitoneum (due to extracellular neutral fat + fatty acids)

  • thickening of bowel wall

  • splenomegaly

  • ascites

  • pleuropericarditis

  • sacroiliitis

• US:

  • echogenic lymph nodes

Dx:	endoscopically guided biopsy of small bowel mucosa, abdominal/peripheral lymph node biopsy
Rx:	long-term broad-spectrum antibiotics (tetracycline)
DDx:	Sprue (marked dilatation, no fold thickening, pronounced segmentation + fragmentation) Intestinal lymphangiectasia (thickened folds throughout small bowel) Amyloidosis Lymphoma

Zenker Diverticulum

• = PHARYNGOESOPHAGEAL DIVERTICULUM

• = outpouching of posterior hypopharyngeal wall = pulsion diverticulum with herniation of mucosa + submucosa through oblique + transverse muscle bundles (pseudodiverticulum) of the cricopharyngeal muscle

Prevalence:	0.01 0.11% (overall); higher in elderly women (50% occur in 7th 8th decade)
Etiology:	cricopharyngeal dysfunction (cricopharyngeal achalasia/premature closure) results in increased intraluminal pressure
Associated with:	hiatal hernia, gastroduodenal ulcer, midesophageal diverticulum, esophageal spasm, achalasia

• compressible neck mass

• upper esophageal dysphagia (98%)

• regurgitation + aspiration of undigested food

• noisy deglutition

• halitosis (= foul breath)

  Location:

  at pharyngoesophageal junction in midline of Killian dehiscence/triangle of Laimer, at level of C5-6

• posterior barium extension in upper half of semilunar depression on the posterior wall of esophagus (cricopharyngeal muscle)

• barium-filled sac extending caudally behind + usually to left of esophagus

• partial/complete obstruction of esophagus from external pressure of sac contents

• partial barium reflux from diverticulum into hypopharynx

• continual growth with successive enlargement

• CXR:

  • air-fluid level in superior mediastinum

Cx:	aspiration pneumonia (30%); esophageal perforation; carcinoma (0.48%)
Rx:	surgical excision

Zollinger-Ellison Syndrome

• = peptic ulcer diathesis associated with marked hypersecretion of gastric acid + gastrin-producing non- islet cell tumor of pancreas

Cause:

• GASTRINOMA (90%)

  • = non- islet cell tumor with continuous gastrin production

• PSEUDO Z-E SYNDROME = Cowley SYNDROME

  • = antral G-cell hyperplasia (10%) = increase in number of G-cells in gastric antrum

  • lack of gastrin elevation after secretin injection

  • exaggerated gastrin elevation after protein meal

Age:

middle age; M > F

• Clinical tetrad:

  • Gastric hypersecretion: refractory response to histamine stimulation test concerning HCl concentration; increased basal secretion (>60% of augmented secretion is diagnostic)

  • Hypergastrinemia >1000 ng/L (during fasting)

  • Hyperacidity with basal acid output >15 mEq/h

  • Diarrhea (30%), steatorrhea (40%): may be sole complaint in 10%, frequently nocturnal; secondary to inactivation of pancreatic enzymes by large volumes of HCl/excessive delivery of acid to small bowel

• severe intractable pain (90%)

• ulcer perforation (30%)

• positive secretin test = increase in serum gastrin level by >200 ng/L after administration of 2 IU/kg of secretin

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• ulcers (atypical location + course should suggest diagnosis):

  Location:	duodenal bulb (65%) + stomach (20%), near ligament of Treitz (25%), duodenal C-loop (5%), distal esophagus (5%)
  Multiplicity:	solitary ulcer (90%), multiple ulcers (10%)

  • recurrent/intractable ulcers

  • marginal ulcers in postgastrectomy patient

    • on gastric side of anastomosis

    • on mesenteric border of efferent loop

• prominence of area gastricae (hyperplasia of parietal cell mass)

• enlargement of rugal folds

• sluggish gastric peristalsis ( hypokalemia)

• wet stomach = dilution of barium by excess secretions in nondilated nonobstructed stomach

• gastroesophageal reflux (common) + esophagitis

• dilatation of duodenum + upper small bowel (fluid overload)

• thickened folds in duodenum + jejunum (edema)

• rapid small-bowel transit time

mnemonic:

FUSED

• Folds (thickened, gastric folds)

• Ulcers (often multiple, postbulbar)

• Secretions increased (refractory to histamine)

• Edema (of proximal small bowel)

• Diarrhea

Cx:	Malignant islet cell tumor (in 60%) Liver metastases will continue to stimulate gastric secretion
Rx:	Control of gastric hypersecretion: H2-receptor antagonist: cimetidine, ranitidine, famotidine Hydrogen-potassium adenosine triphosphatase inhibitor (omeprazole) Resection of gastrinoma if found (because of malignant potential) Total gastrectomy