P1226 - Large Colonic Mantle Cell Lymphoma Presenting with Multiple Lymphomatous Polyposis

Christopher Nguyen, DO¹, Obada Tayyem, MD¹, Sheharyar Merwat, MD¹, Paul Young, MD^2
1University of Texas Medical Branch, Galveston, TX; ²University of Texas Medical Branch at Galveston, Galveston, TX

Introduction: Mantle cell lymphoma (MCL) is a B-cell neoplasm subtype that can involve in the gastrointestinal (GI) tract and uncommonly presents with numerous polypoid lesions throughout the GI tract. Multiple lymphomatous polyposis (MLP) is a rare form of primary GI lymphoma with a poor prognosis. Here we present a case of a large colonic MCL presenting with diffuse polyposis.

Case Description/Methods: A 42-year-old male presented with 8 months of constipation, unintentional weight loss, and occasional bright red blood per rectum. Vitals were within normal limits. Physical exam and lab values were unremarkable. Computed tomography (CT) of the abdomen revealed marked circumferential mural thickening of the ascending colon and cecum with adjacent lymphadenopathy and ileocecal intussusception without bowel obstruction. Colonoscopy showed a lobulated completely obstructing large mass in the ascending colon in addition to severe diffuse nodular mucosa throughout the entire colon. Biopsy revealed cyclin D1 positive lymphocytes diagnostic for mantle cell lymphoma (Figure A-C). CT thorax showed diffuse lymphadenopathy and multiple pulmonary nodules concerning for pulmonary metastasis. Bone marrow biopsy was positive for mantle cell lymphoma involving less than 5% of bone marrow cellularity. The NORDIC protocol consisting of cyclophosphamide, doxorubicin, vincristine, prednisone, rituximab, and cytarabine was initiated with complete remission indicated by positron emission tomography prior to the fourth cycle.

Discussion: Primary gastrointestinal involvement of MCL is rare and accounts for 6-9% of all gastrointestinal B-cell lymphomas. MLP has been reported in marginal B-cell, follicular, and mucosal-associated lymphoid tissue lymphomas however are more associated with MCL. Due to the aggressive nature of MLP, 70% of patients present with advanced malignancy (Ann Arbor classification stage III-IV) and was historically uncurable with an overall survival rate of 3-4 years. Recent novel therapies have significantly improved overall mean survival up to 12.7 years though risk of recurrence remains a concern. This case highlights MLP as a rare manifestation of MCL and the importance of early detection of aggressive primary gastrointestinal lymphoproliferative disorders for optimal treatment outcomes.



Disclosures:


Christopher Nguyen, DO¹, Obada Tayyem, MD¹, Sheharyar Merwat, MD¹, Paul Young, MD². P1226 - Large Colonic Mantle Cell Lymphoma Presenting with Multiple Lymphomatous Polyposis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.