Colonoscopic manifestations of primary colorectal lymphoma

Background and study aims: Little is known about the colonoscopic manifestation of colorectal lymphoma. This article describes the use of colonoscopy for diagnosis of primary colorectal lymphoma. Patients and methods: We analyzed colonoscopic findings in 13 retrospectively collected cases of primary colorectal lymphoma diagnosed between 1990 and 1999 at our hospital. Results: The primary colorectal lymphomas were distinguished into three colonoscopic types: a) the mucosal type, which included six lymphomas (46%), which were classified into two subtypes, erosive (two lymphomas) and ulcerative (four lymphomas); b) the polypoid type, which included three lymphomas (23%); and c) the massive type, which included four (31%). The proportion of patients with T-cell lineage lymphoma (5 of 12, 42%) was higher than in previous studies. Three cases were diagnosed as enteropathy-associated T-cell (EAT)-like lymphoma: one presenting with multicentric ulcerations, one as a massive type and another as a polypoid type. Of those with B-cell lineage lymphoma (7 of 12, 58%), three presented as massive type, two as polypoid type and two as erosive subtype. Conclusions: Based on the analysis of colonoscopic records, we have proposed three main types of primary colorectal lymphoma. An unusually high proportion of T-cell lineage lymphomas was noted, but as the number of cases was low, further study is still needed for confirmation.