Which feature distinguishes Crohn disease from ulcerative colitis in the colon?

Which feature distinguishes Crohn disease from ulcerative colitis in the colon?

• A. Transmural inflammation with skip lesions and granulomas is Crohn; continuous mucosal inflammation with crypt abscesses is UC.
• B. Fistulas formed with granulomas is typical of UC.
• C. Mucosal ulceration with crypt abscesses only is Crohn.
• D. Granulomas with transmural inflammation is UC.

Answer: (A)

The feature being tested is how the inflammation spreads through the bowel wall and how it appears in the colon. Crohn disease typically involves full-thickness (transmural) inflammation and can affect any part of the GI tract in a patchy, discontinuous way (skip lesions); granulomas may be present on biopsy. Ulcerative colitis, by contrast, shows continuous mucosal (and submucosal) inflammation starting in the rectum and extending proximally, with crypt abscesses being a characteristic histologic finding. So the best answer reflects that Crohn is transmural with skip lesions and granulomas, while UC is continuous mucosal inflammation with crypt abscesses. The other options mix up these patterns: fistulas are more typical of Crohn, not UC; Crohn is not limited to mucosa with only crypt abscesses; and UC does not characteristically have granulomas or transmural inflammation.

The feature being tested is how the inflammation spreads through the bowel wall and how it appears in the colon. Crohn disease typically involves full-thickness (transmural) inflammation and can affect any part of the GI tract in a patchy, discontinuous way (skip lesions); granulomas may be present on biopsy. Ulcerative colitis, by contrast, shows continuous mucosal (and submucosal) inflammation starting in the rectum and extending proximally, with crypt abscesses being a characteristic histologic finding.

So the best answer reflects that Crohn is transmural with skip lesions and granulomas, while UC is continuous mucosal inflammation with crypt abscesses. The other options mix up these patterns: fistulas are more typical of Crohn, not UC; Crohn is not limited to mucosa with only crypt abscesses; and UC does not characteristically have granulomas or transmural inflammation.