A case of intestinal T‐cell lymphoma, not otherwise specified, that showed characteristic findings by magnified endoscopy combined with narrow‐band imaging

T‐cell lymphoma in the gastrointestinal tract (intestinal T‐cell lymphoma, [ITCL]) is rare. ITCL, not otherwise specified (ITCL, NOS) which is a type of ITCL is particularly rare. There are few case reports of ITCL, NOS but no previous reports describe its endoscopic features. In this report, the 69‐year‐old man was diagnosed with ITCL, NOS. Colonoscopy revealed the elevated legion and edematous mucosa with focal depressions in the lower rectum. On the depressed legions, magnifying endoscopy combined with narrow‐band imaging detected the disappearance of glandular structure and branching abnormal blood vessels like a tree. These findings were similar to the tree‐like appearance, which has been described as a unique feature of gastric mucosal‐associated lymphoid tissue lymphoma. The targeted biopsy of the tree‐like appearance showed abnormal histopathological findings which fit the definition of ITCL, NOS. He was treated with chemotherapy and achieved complete remission. As is the case of gastric mucosal‐associated lymphoid tissue lymphoma, the tree‐like appearance is possibly the unique sign of ITCL, NOS. We report the endoscopic features of ITCL, NOS and show characteristic findings by magnifying endoscopy combined with narrow‐band imaging.