Fig. 2.

Histologic findings of Crohn’s disease. (A) Hypertrophy and hyperplasia of the submucosa and muscularis propria are present. (B) Chronic inflammation with lymphoid aggregates and lymphoid follicles is dominant. (C) Although chronic inflammation is predominant, active inflammation that consists of extensive neutrophilic infiltrates is also noted. (D) Fibromuscular hyperplasia of damaged submucosal vessels causes slow blood flow. (E) Neural hypertrophy is also noted. (F) Trichrome stain reveals that dissection between the hyperplastic smooth muscle bundles is interspersed with fibrosis.