Diagnosis and Outcome of Extranodal Primary Intestinal Lymphoma in Inflammatory Bowel Disease: An ECCO CONFER Case Series

Background: There is a small but measurable increased risk of lymphoma in inflammatory bowel disease [IBD], with a suggestion that primary intestinal lymphoma [PIL] in IBD is associated with inflamed tissue and immunosuppressant use, mainly thiopurines. Methods: This multicentre case series was supported by the European Crohn's and Colitis Organisation [ECCO] and performed as part of the Collaborative Network of Exceptionally Rare case reports [CONFER] project. Clinical data were recorded in a standardized case report form. Results: Fifteen patients with intestinal lymphoma from eight centres were included (12 males, 11 patients with Crohn's disease [CD], mean age 47.8 [±16.4 SD, range 26-76] years at lymphoma diagnosis). Lymphoma type was diffuse large B-cell lymphoma [DLBCL] in eight, Hodgkin's disease in two, mucosa-associated lymphoid tissue [MALT] lymphoma in three, and single cases of immunoblastic lymphoma and indolent T-cell lymphoma. Lymphoma was located within the IBD-affected area in ten patients. At lymphoma diagnosis, nine patients had a history of azathioprine or anti-tumour necrosis factor [TNF] use. Lymphoma was diagnosed at a mean time of 10.4 [±7.07, 1-24] years after IBD diagnosis in 11 patients, prior to IBD in two and concurrently in two. Sustained remission over a median follow-up time of 6.5 [1.5-20] years was achieved in ten patients after treatment; five of them had started biological therapy [including anti-TNFs, vedolizumab and ustekinumab] for active CD subsequent to their PIL treatment. Conclusion: In this small case series, two-thirds of patients developed lymphoma in the IBD-affected area, and almost two-thirds had a history of thiopurine or anti-TNF use. Biologics were restarted without recurrence of lymphoma in half of the remitters.