A very rare case of malignant lymphoma of the duodenum is reported. A 67-year-old woman was found to have a cobble stone-like lesion around the papillar of Vater by screening gastroduodenalscope. Histopathology revealed follicular malignant lymphoma. Pylorus preserving pancreatoduodenectomy was successfully performed. The patient has been alive without tumor recurrence since 24 mouths postoperatively. There have been 70 cases of malignant lymphoma of the duodenum in the Japanese reports. And then, follicular lymphoma of the duodenum was detected three cases. Two of them were cobble stone-like appearance endoscopically.
