1578 A Rare Follicular Lymphoma of the Colon

Abstract

INTRODUCTION: Here we present a case of intestinal follicular lymphoma (IFL) originating in the colon. Pathology was confirmed from multiple institutions and the authors of this report could only find a few such instances in literature. We will go through the case, the diagnosis, endoscopic pictures, as well as patient outcome. CASE DESCRIPTION/METHODS: A 60 year old male presented for a routine screening colonoscopy. A single polyp, measuring between 10 and 20 mm, was found in the colon, 30 cm from entry site and removed with snare cautery polypectomy. Initial pathology was consistent with low grade B-Cell Lymphoma of possible marginal zone origin that was positive for BCL2, CD20, CD43, and Ki-67. A year later patient presented for follow up colonoscopy in which two additional polyps were found, one at the splenic flexure, one at 50 cm. Both of their pathology was CD10, CD20 positive and consistent with follicular lymphoma, grade 2. This finding was also confirmed by a reputable pathologist in a different health system. The recent polyps do bring into question as to whether the initial polyp was also follicular lymphoma. Patient underwent a subsequent bone marrow biopsy at the time that showed small atypical lymphoid aggregates. DISCUSSION: Intestinal follicular lymphomas (IFL) are a subtype of Non-Hodgkin's lymphoma that account from anywhere to 1-3.6% of all cases. Although there are not many cases present in literature, the authors did find a study indicating older caucasians were more prone to this diagnosis. While some patients present for evaluation of gastrointestinal complaints, our patient was asymptomatic when he presented for a routine colonoscopy. Multiple polyps were found that were consistent with lymphoma pathology. Most of these cases present on endoscopic evaluation as elevated lesions with no erosions or ulcerations. Consistent with primary follicular lymphomas, our patient's pathology also exhibited positive CD10 and CD20 immunohistochemical markers. Takata et al. reviewed prior cases of IFL and determined the small intestine is the most common site. However, multiple reports site that primary colon IFL only accounts for about 1-2% of IFL. Despite its rarity, the prognosis is fairly well with Chouhan et al. indicating a 5 year OS rate of 71.5%. The traditional FLIPI and FLIPI2 prognostic scales could not be used in this case as there have not been enough IFL cases to prove the effectiveness of this method. Our patient has since been stable in the 4 years following his latest polyp removal.