Primary Rectal Mucosa-Associated Lymphoid Tissue Lymphoma: Report of a Case with Extensive FISH Study

摘要

Primary rectal mucosa-associated lymphoid tissue (MALT) lymphoma is a very rare entity with scarce cytogenetic/molecular genetic data. We presented a polypoid rectal MALT lymphoma in a 75 year-old male. The tumor comprisedsmall atypical lymphocytes forming focal lymphoepithelial lesions and expressing CD20 but not CD5, CD23,CD43, or cyclin D1. They were negative for translocations involving IGH, MALT1, BCL2, BCL6, and CCND1 genes, andthe copy numbers of chromosomes 3, 12, and 18 were normal by fluorescent in situ hybridization. The patient was disease-free for 83 months after oral endoxan and prednisolone and concurrent local radiotherapy. With increasing awarenessof this disease and accumulating reports on clinicopathological and molecular data, the pathogenesis, best treatment strategyand clinical course of such tumors will be uncovered.