Mantle Cell Lymphoma Presenting as Chronic Polyposis

Abstract

Purpose: A 71-year-old male presented for screening colonoscopy. Last colonoscopy, 10 years ago was negative for polyps, dysplasia or cancer. Past medical history was significant for thromobocytopenia, diagnosed in 2003. Family history was negative for GI cancer and polyps. Physical examination was negative. Colonoscopy from rectum to cecum was negative for any polyps, dysplasia or cancer. In Feb 2011, patient presented for his colonoscopy with no current acute GI symptoms. Colonoscopy revealed numerous 3-6 mm sessile polyps of benign appearance diffusely throughout the colon. Polypectomies showed extensive involvement by a markedly atypical lymphoid infiltrate with a nodular architectural pattern. The cells were monomorphous small to intermediate in size with uniform stippled chromatin, absence of nucleoli and mildly irregular nuclear contours. A panel of immunostains was performed showing atypical lymphoid infiltrate that were overwhelmingly B cell immunophenotype with CD 20 immunostain. There was also co expression of CD 5 and nuclear positivity for cyclin D-1. Based on the morphological findings and immunoprofile, the lymphoid infiltrate represents a neoplastic B cell lymphoproliferative disorder best classified as Mantle Cell lymphoma. In this clinical setting the B cell neoplasm was presenting as lymphomatous polyposis. CT and PET scans revealed metastases involving the jugular chain, supraclavicular, axillary, mediastinal, hilar and subcarinal lymph nodes. The spleen was mildly enlarged. After six cycles of Bendamustine and Rituximab therapy, repeat colonoscopy 9 months later revealed complete resolution of polyposis.Figure 1: Polyp at the transverse colon.Figure 2: Cyclin D immunostain.