ABSTRACT
Introduction: Mantle cell lymphoma (MCL), a rare non-Hodgkin's lymphoma, exhibits a genetic translocation causing CCND1 gene overexpression, affecting 5% of NHL cases, predominantly in males aged 60-70. Typically diagnosed with advanced symptoms, MCL involves widespread disease and organ spread, being aggressive and incurable with a 1.8-9.4-year average survival. Optimal treatment depends on disease aggressiveness and age. Multiple lymphomatous polyposis (MLP), a rare MCL subtype in the GI tract, is usually present with GI symptoms. Case Presentation: A 71-year-old woman was diagnosed with asymptomatic MLP during MCL staging who underwent thoracentesis due to large right pleural effusion and significant axillary lymphadenopathy and was treated with a chemotherapy regimen of rituximab/cytarabine and later transitioned to bendamustine/rituximab. This patient eventually underwent a bone marrow biopsy and later a bone marrow transplant. Conclusion: We present a unique case of asymptomatic MLP, emphasizing the importance of early detection for the poor prognosis of MLP with a mean survival of less than 3 years.