AIM: To evaluate the endoscopic manifestations and prognoses of gastrointestinal (GI) mantle cell lymphoma (MCL). METHODS: A database search at the Department of Pathology of Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences revealed 57 MCL patients with GI involvement. Clinical records were available for 35 of the 57 patients from 21 institutions, and those 35 patients were enrolled in this study. We summarized the gross types of endoscopic features, event-free survival (EFS), and overall survival (OS) of those patients.RESULTS: Of the 35 patients, GI involvement in the esophagus, stomach, and duodenum was found in 2 (5.7%), 26 (74.3%), and 12 (34.3%) patients, respectively. Twenty-one of the 35 patients underwent colonoscopy; among them, GI involvement in the ileum, cecum, colon, and rectum was found in 10 (47.6%), 3 (14.3%), 12 (57.1%), and 10 (47.6%), respectively. Various lesions, such as superficial, protruded, fold thickening, or ulcerative, were found in the stomach, whereas multiple lymphomatous polyposis (MLP) was dominant from the duodenum to the rectum. Twelve patients were treated with a hyper-CVAD/MA regimen, and they had better OS (3-year rate, 88.3% vs 46.4%, P < 0.01) and better EFS (3-year rate, 66.7% vs 33.8%, P < 0.05) than the remaining 23 patients who were not treated with this regimen. CONCLUSION: MLP was a representative form of intestinal involvement, whereas a variety of lesions were found in the stomach. The hyper-CVAD/MA regimen may improve survival in these patients. AIM: To evaluate the endoscopic manifestations and prognoses of gastrointestinal (GI) mantle cell lymphoma (MCL). METHODS: A database search at the Department of Pathology of Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences revealed 57 MCL patients with GI Clinical records were available for 35 of the 57 patients from 21 institutions, and those 35 patients were enrolled in this study. We summarized the gross types of endoscopic features, event-free survival (EFS), and overall survival (OS) of those patients .RESULTS: Of the 35 patients, GI involvement in the esophagus, stomach, and duodenum was found in 2 (5.7%), 26 (74.3%), and 12 (34.3%) patients, respectively. Twenty-one of the 35 patients underwent colonoscopy; among them, GI involvement in the ileum, cecum, colon, and rectum was found in 10 (47.6%), 3 (14.3%), 12 (57.1%), and 10 (47.6%), respectively. Various lesions, such as superficial, protruded, fold thickening, or ulcerative, were found in the stomach, while multiple lymphomatous polyposis (MLP) was dominant from the duodenum to the rectum. Twelve patients were treated with a hyper-CVAD / MA regimen, and they had better OS (3-year rate, 88.3% vs 46.4 %, P <0.01) and better EFS (3-year rate, 66.7% vs 33.8%, P <0.05) than the remaining 23 patients who were not treated with this regimen. CONCLUSION: MLP was a representative form of intestinal involvement, a variety of lesions were found in the stomach. The hyper-CVAD / MA regimen may improve survival in these patients.