Primary colorectal lymphoma comprising both components of diffuse large B-cell lymphoma and mucosa-associated lymphoid tissue lymphoma combined with cytomegalovirus colitis

摘要

Gastrointestinal (GI) lymphomas account for 5-20 % of extranodal lymphomas [1, 2], with the stomach being the most common site, followed by the small intestine (ileum 60-65 %, jejunum 20-25 %, duodenum 6-8 %, and colorectal lymphomas 6-12 %) [3-5]. Primary colonic lymphoma is infrequent among colorectal neoplasms and most are histologically classified as diffuse large B-cell lymphoma (DLBCL). However, recent reports suggest increased rates of mucosa-associated lymphoid tissue (MALT) lymphoma [6]. It is possible that MALT lymphoma transforms to DLBCL, although the mechanisms remain poorly understood.Here we report a case of primary malignant lymphoma with a cytomegalovirus (CMV) infection in the lower GI tract and discuss the malignant transformation into DLBCL and CMV-related lymphomagenesis.