443 Extranodal marginal zone lymphoma following prolonged treatment with adalimumab in a young patient with refractory ulcerative colitis and Ehlers-Danlos syndrome

Introduction/Objective Patients receiving adalimumab to treat chronic autoimmune diseases have a three-fold higher incidence of lymphoma compared to the general U.S. population. Recognizing these low-grade iatrogenic lymphomas within colonic biopsies obtained to monitor inflammatory bowel disease can be challenging. Methods/Case Report A 24-year-old woman with Ehlers-Danlos syndrome (EDS) and refractory ulcerative colitis (UC) received prolonged treatment with adalimumab. Routine colonoscopy demonstrated granular and markedly inflamed mucosa. Microscopy revealed features of UC (cryptitis, crypt abscesses, gland distortion, atrophy, dropout), as well as increased lymphocytes and plasma cells forming prominent, vaguely nodular submucosal aggregates. The lymphocytes were small, positive for CD20 and BCL2, and negative for CD10, BCL6, and T cell markers. The findings were interpreted as consistent with extranodal marginal zone lymphoma arising within a background of active UC. Results NA Conclusion General pathologists should have a low threshold for immunohistochemical characterization of prominent lymphoid aggregates in patients with refractory UC on prolonged immunosuppressant therapy. The existence of a pre-existing inherited disorder, EDS, further illustrates the importance of heightened clinical suspicion, as EDS-mediated intestinal dysmotility may exacerbate UC, necessitating powerful immunosuppressant therapies that predispose to lymphoma.