Primary colorectal T-cell lymphoma

We report here a case of primary colorectal T-cell lymphoma in a 49-year-old man. Eighteen years previously, he was diagnosed as having ulcerative colitis based on the findings of colonoscopy and a barium enema. Since then, he had been treated with salicylazosulfapyridine until the most recent episode. He was refered to our clinic with the chief complaint of abdominal pain and excretion of mucus, and for a workup of bowel lesions. Physical examination results were not remarkable, except for the presence of low-grade fever. Total colonoscopy showed multiple shallow ulcers and aphthoid erosions through the entire colon and rectum, except for the descending colon. Endoscopic findings of the descending colon were normal, which was different from the findings of the active stage of ulcerative colitis. Biopsy specimens from the colon and rectum with ulcerations and aphthoid erosions showed a diffuse proliferation of medium-sized to large atypical lymphoid cells with irregular and indistinct nucleoli, thus revealing malignant lymphoma, diffuse pleomorphic type. The lymphoma cells were positive for CD2, CD3, CD5, CD8, and T-cell receptor (TCR) beta F1, but negative for CD4, CD19, CD20, CD103, and CD56. Southern blotting revealed rearrangement of TCR. Based on these findings, the patient was diagnosed as having high-grade T-cell lymphoma. The findings of computerized tomography of the chest and abdomen, gallium scintigraphy, and abdominal ultrasonography were all normal. There were no abdominal lesions throughout the esophagus, stomach, duodenum, and small intestine. As the patient refused total proctocolectomy, he was treated with one course of CHOP (cyclophosphamide, vincristine, adriamycin, and prednisolone) and subsequently with three courses of ProMACE-CytaBOM (consisting of cyclophosphamide, adriamycin, etoposide, cytarabine, bleomycin, vincristine, methotrexate, and prednisolone). After the therapy, improvement of the colorectal lesions was observed, though lesions clearly still remained. To our knowledge, this is the first case report of primary colorectal T-cell lymphoma with cytotoxic/suppressor T-cell phenotype.