Rectal mucosa shows superficial erosions and moderate infiltration by lymphocytes and plasma cells with few neutrophils indicating activity. There is associated focal formation of lymphoid follicles having intact germinal centers. Mucigenic cells are intact and no evidence of crypt abscesses. No evidence of specific granulomas. No evidence of atypia or malignancy.
Multiple rectal ulcers and erosions.
Soft tissue fragments collectively measured 1 cm, totally embedded.
Rectum, colonoscopic biopsy: