發炎性腸病變

CROHN'S DISEASE

Idiopathic, chronic, and recurrent inflammatory bowel disease with variably distributed but usually sharply delimited, typically transmural involvement of bowel at any level by noncaseating granulomatous inflammation, ulceration, and fibrous constriction
Onset usually in 20s and 30s; higher incidence in U.S., U.K., and Scandinavia than in U.S.S.R., South America
White > black; female ≥ male
Often intermittent attacks of diarrhea, fever, abdominal pain; attacks can be triggered by physical or emotional stress
Most commonly affects terminal ileum (65-75%) and/or colon (50-70%); colonic involvement alone in only 20-30%
Frequently "skip lesions" in Gl tract, with intervening unaffected segments
Related lesions may be seen in skin, bone, muscle, lung Pathogenesis unknown: theories include infectious, immunologic, vasculitis, etc.
Inflammation in wall initially edematous, but then becomes fibrous with longitudinal mucosal ulcerations, creeping fat, luminal narrowing, fissure formation (25-30%), and fistulous tracts
Histologically, transmural inflammation, relatively poorly formed noncaseating granulomas (present in only 65%), lymphoid aggregates and germinal centers, dilation or sclerosis of lymphatic channels

ULCERATIVE COLITIS (UC)