1640 Case Report: Diffuse Large B-Cell Lymphoma Presenting as Multiple Lymphomatous Polyposis

Abstract

INTRODUCTION: Diffuse Large B Cell Lymphoma (DLBCL) is the most common type of Non-Hodgkin’s Lymphoma (NHL) in the U.S. accounting for one third of all newly diagnosed NHL’s. The gastrointestinal (GI) tract is the most common site of extra nodal involvement with mucosa-associated lymphoid tissue (MALT) lymphoma and DLBCL accounting for 70-95% of all GI lymphomas. Multiple lymphomatous polyposis (MLP) is a rare presentation of GI lymphoma characterized by diffuse proliferation of lymphocytes that present as multiple polypoid tumors involving long segments of the GI tract. MLP classically presents in mantle cell lymphoma, but can also present, although less frequently, in MALT and follicular lymphomas. We present a unique case of a patient that presented initially with lower GI bleed and was subsequently found to have extensive polypoid lesions in the entire colon. Histological evaluation revealed DLBCL, a rare etiology of MLP. CASE DESCRIPTION/METHODS: A 93-year-old woman with chronic thrombocytopenia suspicious for low-grade MDS and history of a large tubulovillous adenoma without high-grade dysplasia or cancer for which she had undergone a right hemicolectomy, presented to the emergency department with intermittent rectal bleeding, severe anemia, fatigue, decreased appetite, and a 17 pound weight loss over the past 2 months. Her hemoglobin level on admission was 6.5 g/dL (baseline Hgb 11 g/dL) and all other cell counts were otherwise normal. Her last colonoscopy ten years ago was normal and she was given the choice to continue or forego colon screening given her age. She had no family history of colon polyps or colorectal cancer. Colonoscopy revealed approximately 50-100 sesile polypoid lesions from the ileocolonic anastomosis to the distal rectum, ranging in size from 2-40 mm. The larger lesions were predominantly located in the proximal colon and were ulcerated and friable. Multiple biopsies were obtained and pathology results revealed diffuse large B-Cell lymphoma. Further studies revealed stage IV DLBCL without bone marrow involvement and she was started on mini R-CHOP chemotherapy. DISCUSSION: Although DLBCL is a rare cause of MLP, it should be included in the differential diagnosis in patients with multiple polypoid lesions throughout the colon that do not fit the typical phenotype for hereditary polyposis syndromes. Lymphomas associated with MLP include MALT and follicular lymphomas; however, DLBCL and other less common lymphomas should be considered when evaluating patients with this entity.