Ulcerative Colitis

 Pathology

• Predominantly mucosal disease, possible auto-immune producing crypt abscesses
• Usual age at onset is 20-40; another peak at 60-70
• Equal male:female ratio 

Clinical

• Recurrent episodes of bloody diarrhea
• Electrolyte depletion
• Abdominal pain
• Fever
• Periods of exacerbation and remission
• Iritis, erythema nodosum, pyoderma gangrenosum
• Pericholangitis, chronic active hepatitis, sclerosing cholangitis, fatty liver
• Spondylitis, peripheral arthritis, RA (10-20%)
• Thrombotic complications 

Location

• Begins in rectum with retrograde progression
• Rectosigmoid involved 95%; continuous involvement of left colon
• Terminal ileum in 5-10% with backwash ileitis 

Imaging Manifestations 

• Acute inflammatory stage
• Spasm and irritability
• Fine mucosal granularity=earliest finding on air-contrast BE
• Spiculated, serrated bowel margins from tiny, multiple ulcerations
• Collar button ulcers-from undermining (not specific for UC)
• Double-tracking=long, longitudinal ulcers in submucosa    
• Thumbprinting=from edema of wall
• Pseudopolyps=scattered islands of edematous mucosa in a sea of ulcerated mucosa
• Widening of the presacral space 

• Subacute stage
• Coarser, more granular mucosa
• Inflammatory polyps= frondlike lesions of inflamed mucosa 

• Chronic stage
• Shortening of the colon=may be from spasm of longitudinal muscles or from irreversible fibrosis (lead-pipe colon)
• Loss of haustrations on left side of colon
• Postinflammatory polyps=filiform polyps=long worm-like lesions
• Backwash ileitis (5-10%)=wide open ileocecal valve and dilated terminal ileum                                                                                      

Differential Diagnosis

• Crohn’s disease–skip lesions: R colon; TI abnormal
• Cathartic colon-loss of haustrations on Right side of colon; rectum spared
• Familial polyposis–multiple polyps but no inflammatory changes
• Radiation ileitis–should have other loops involved and appropriate hx
• Lymphoma–should have tumor masses, less spasm
• Amebiasis–cone-shaped cecum 

Extra-intestinal Manifestations

• Fatty infiltration of the liver
• Gallstones (28-34%)
• Sclerosing cholangitis
• Bile duct carcinoma
• Amyloidosis
• Urolithiasis:oxalate/uric acid stones
• Migratory arthritis
• Sacroiliitis and ankylosing spondylitis
• Erythema nodosum and uveitis 

Complications

• Toxic megacolon
• Adenocarcinoma of the colon (1-16%)
• Increased risk of developing ca of colon with long-standing (usually more than 25 years) ulcerative colitis
• Higher incidence of multiple carcinomas
• Usually involve distal transverse colon, descending colon and rectum
• May present with smooth, tapering edges and resemble a benign stricture or may be annular constricting lesions
• Colonic strictures (10%)
• Smoothly tapering edges, usually single, commonly in sigmoid; must be differentiated from ca

 
Ulcerative Colitis: Barium enema examination demonstrates loss of haustral folds in the entire descending colon with small ulcerations suggested. The colon has a "lead-pipe" appearance. The distribution and appearance are suggestive of ulcerative colitis.

Ulcerative Colitis: Barium enema examination demonstrates loss of haustral folds in the entire descending colon (white arrow) with a granular appearance to the mucosa suggesting small ulcerations. The distribution and appearance are suggestive of ulcerative colitis.