Severe Chronic Anemia and Tumor-Mimicking Colonic Lesions as an Atypical Presentation of Crohn's Colitis.

Crohn's colitis may rarely present with severe bleeding and tumor-mimicking colonic lesions, creating concern for malignancy. A 20-year-old bedridden man with cerebral palsy had recurrent hematochezia and transfusion-dependent microcytic anemia, with hemoglobin 2.8 g/dL. Colonoscopy showed diffuse raised island-like plaques with vascular-pattern loss, rectal sparing, edematous ileocecal valve, and an oozing transverse-colon lesion requiring clipping. Multisite biopsies showed chronic active colitis with crypt distortion, cryptitis, and crypt abscesses, without granulomas, dysplasia, or malignancy. Tissue tuberculosis polymerase chain reaction was negative; interferon-gamma release assay was unavailable. Crohn's colitis was favored by clinicopathologic correlation. Bleeding resolved after corticosteroids, infliximab, and azathioprine; hemoglobin improved to 9.9 g/dL.