PRIMARY GASTROINTESTINAL T-CELL LYMPHOMA RESEMBLING MULTIPLE LYMPHOMATOUS POLYPOSIS

An extremely rare case of primary gastrointestinal T-cell lymphoma inv olving the stomach and intestine is reported. Radiographic and endosco pic examinations showed multiple polypoid lesions covered by a normal- appearing mucosa in the stomach, duodenal bulb, and terminal ileum and numerous small aphthoid lesions throughout the entire colorectum. His topathologic, immunohistochemical, and polymerase chain reaction studi es were performed using paraffin-embedded or fresh-frozen specimens fr om endoscopic biopsies and endoscopic mucosal resections. All lesions were composed of small, atypical lymphoid cells, which were classified as low-grade pleomorphic lymphoma. The tumor cells expressed CD3, CD4 , and the T-cell receptor gamma gene phenotype as well as human mucosa l lymphocyte 1 antigen, suggesting that the lymphoma cells were derive d from intraepithelial T lymphocytes. This is the First description of primary gastrointestinal T-cell lymphoma with expression of human muc osal lymphocyte 1 antigen and a novel morphology resembling multiple l ymphomatous polyposis.