Characteristics Of Lymphoma In Patients With Inflammatory Bowel Disease: A Systematic Review.

INTRODUCTION Lymphoma is a dreaded complication of inflammatory bowel diseases (IBD). Knowledge about lymphoma in patients with IBD is limited to epidemiological data and risk factors description. We performed a systematic review to describe clinical characteristics and prognosis of lymphoma in patients with IBD. METHODS Electronic databases were searched up to 1 st June 2020. All published clinical characteristics of lymphoma occurring in patients with IBD were collected. RESULTS Eleven studies were included. A total of 589 lymphomas were described in patients with IBD. As seen in de novo lymphoma, non-Hodgkin's lymphoma (NHL) was the most common histological subtype (83.9%). Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma were the most represented NHL in patients with IBD (30% and 13% respectively). Two main differences were observed in comparison to de novo lymphoma: primary intestinal lymphoma (PIL) represented a large part of lymphoma in patients with IBD (22% to 75%) whereas mucosa-associated lymphoid tissue (MALT) lymphoma was under-represented. Epstein-Barr virus (EBV) positive status was observed in a large part of tumors (44 to 75%). Survival data of lymphoma in patients with IBD were similar to that of de novo lymphoma. DISCUSSION This systematic review first highlights that PIL (especially DLBCL subtype) is significantly more frequent in patients with IBD and represents the most common entity. Conversely, MALT lymphoma is extremely rare in IBD population. However, the overall quality of the evidence is low. Further studies are required to better define lymphoma characteristics in patients with IBD.