Marginal zone lymphoma of the colon: case series from a single center and SEER data review.

Colon extranodal marginal zone lymphoma (EMZL) is poorly characterized in the literature. We performed a retrospective review of patients with colon EMZL at our institution and from the Surveillance Epidemiology and End Results (SEER) database. Eight patients were identified in our institution with majority (88%) presenting with stage-I disease. Initial management included active surveillance, polypectomy followed by surveillance, and surgical resection followed by chemotherapy. One patient with concurrent prostate carcinoma received radiation to the rectum. Initial therapy led to complete remission in five out of six treated patients with four of them maintaining remission at 88 months. SEER database identified 361 patients with stage-I colon EMZL. Overall survival for this cohort was 73.9% at 10 years with no significant difference in outcomes between treatment groups. Our single institution experience and the SEER data analysis emphasize indolent nature of colon EMZL and need for non-aggressive therapeutic approaches.