Which of the following are predominant histologic features of Crohn’s disease?

a. The presence of granulomas involving the bowel wall and mesenteric lymph nodes

b. Transmural inflammation

c. Fissures and ulceration extending into the muscularis propria

d. Chronic fibrotic changes

Crohn’s disease can affect any part of the gastrointestinal tract with the most common site being the ileocecal region. The acute, active phase is marked by aphthous mucosal ulcerations, lymphoid aggregates, and granulomas present in both the bowel wall, adjacent lymph nodes, and in other organs. Transmural inflammation is present with characteristic fissures and ulcers extending deep into the muscularis propria. The acquiescent or healing phase of Crohn’s disease is marked by fibrosis with late stricture formation and chronic ulceration.