Abstract
A 77-year-old man complained of weight loss and tarry stools. Gastroscopy revealed a duodenal ulcer and multiple duodenal erosions. Contrast-enhanced abdominal computed tomography revealed severe circumferential wall thickening of the descending colon, sigmoid colon, and rectum. 18F-fluorodeoxyglucose positron emission tomography showed diffuse uptake in the colorectal wall. Colonoscopic examination revealed focal hyperemia and edema of the mucosa, and a biopsy of colonic mucosal tissue showed the characteristic histological features of T-cell lymphoma. An inguinal lymph node biopsy revealed the characteristic histological features of angioimmunoblastic T-cell lymphoma (AITL). The lower digestive tract is an unusual site for extranodal AITL.
