Blastoid Mantle Cell Lymphoma Presenting as an Isolated Cecal Mass.

Blastoid mantle cell lymphoma (B-MCL) is a rare and aggressive subtype of B-cell non-Hodgkin lymphoma characterized by a high proliferation index and poor prognosis. Gastrointestinal (GI) involvement, which is common in systemic mantle cell lymphoma (MCL), rarely presents as an isolated lesion. Herein, we describe a unique case of B-MCL presenting as an isolated cecal mass. The patient experienced acute-onset abdominal pain and melena and was found to have cecal wall thickening on imaging, with regional lymphadenopathy. Colonoscopy revealed a large ulcerated polypoid lesion in the cecum, and histopathology confirmed the diagnosis of B-MCL. The patient completed 4 cycles of bendamustine/rituximab regimen but was terminally extubated due to clinical deterioration. Although infrequent, MCL should be considered in the differential diagnosis of isolated GI masses. This case adds to the limited literature on B-MCL, which could potentially help with the formulation of diagnostic and treatment algorithms for this rare pathology.