(A) Case no. 1. (B and C) Case no. 2. (D) Case no. 3. (E) Case no. 4. (A, B, D, and E) Duodenal biopsies showing total villous atrophy with crypt hyperplasia and infiltration of lamina propria by nonatypical inflammatory cells (Hematoxylinandeosin; original magnification × 10). (C) Jejunal biopsy showing villous atrophy and ulcerations with regenerative epithelial changes on the border of ulcerations; no evidence of lymphoma.