Mantle cell lymphoma (MCL) is a subtype of B-cell non-Hodgkin lymphoma, mainly affecting extranodal sites. The gastrointestinal system is the most affected site by MCL. Multiple lymphomatous polyposes in endoscopy are the most usual manifestation of MCL. Solitary lesions are less common; however, concurrent involvement of different organs is rarer.

: A 52-year-old man with significant weight loss and intermittent fever was admitted to the emergency department due to severe abdominal pain. He underwent a laparotomy that revealed duodenal ulcer perforation. Further evaluations were performed, including esophagogastroduodenal endoscopy (EGD) and colonoscopy. Diffuse prominence of gastric folds in EGD, multiple variable size polyps in the rectum and left colon, and a large fungated mass in the cecum extending to the proximal part of ascending colon in the colonoscopy were noted. Numerous biopsies were taken that revealed concurrent MCL. Chemotherapy was initiated, which led to the lesions' disappearance in re-endoscopy and re-colonoscopy. Multi-dimensional computed tomography (MDCT) turned to normal manifestations, as well.

Recognition of such atypical presentations for the concurrent involvement of different organs in MCL should be concisely considered, and future diagnostic and prognostic assessments are required.