A 62-year-old man who had been diagnosed with adult T-cell leukemia (ATL) and received chemotherapy and peripheral blood stem cell transplantation, had a loss of appetite and vomiting on the 89th day after transplantation. Upper and lower endoscopic examinations were performed. Reflecting the dense lymphocyte infiltration along the villous structure, it was observed as multiple white granular elevations on upper endoscopic examination. It was suggested that gastrointestinal lesions including those in the duodenum are a single disease as a systemic lesion, which may indicate a reduction in immunological ability and the disease state. If gastrointestinal symptoms appear during ATL therapy, the gastrointestinal tract should be searched to exclude cytomegalovirus infection and graft-versus-host disease, and the presence of multiple duodenal elevations may indicate ATL infiltration.
