2059 A Case of Hepatosplenic T-cell Lymphoma in a Patient on Vedolizumab for Crohn’s Disease

Abstract

INTRODUCTION: Hepatosplenic T-cell lymphoma (HSTCL) is a rare malignancy, most commonly affecting young males with often fatal prognosis. In patients with inflammatory bowel disease (IBD), HSTCL has been associated with thiopurine analog and tumor necrosis factor (TNF)-α inhibitor therapy; particularly when used in combination, the risk increases up to 4 fold. Development of HSTCL has not been reported in association with vedolizumab. CASE DESCRIPTION/METHODS: A 22-year-old male with severe, stricturing colonic Crohn’s disease of 10 years duration, on vedolizumab monotherapy every 4 weeks for 15 months, was incidentally noted to be pancytopenic in October 2016 and subsequently diagnosed with HSTCL by bone marrow biopsy. Previous IBD therapies included mesalamine, azathioprine, infliximab, adalimumab, intravenous immunoglobulin (IVIG), budesonide, certolizumab pegol and most recently 6 mercaptopurine (6-MP). The 6-MP was discontinued 1 year prior to HSTCL diagnosis. He achieved remission with chemotherapy, followed by autologous stem-cell transplant in September 2017. Unfortunately his disease relapsed only a few months later. He achieved a second remission with salvage chemotherapy, and proceeded to allogeneic bone marrow transplant in April 2018. Since diagnosis of HSTCL, he did not receive any therapy for Crohn’s disease and has been asymptomatic from his IBD. Colonoscopy demonstrated complete endoscopic and histologic remission as well. On last bone marrow biopsy, over 200 days post-transplant, there was no evidence of HSTCL relapse 24 months following HSTCL diagnosis. DISCUSSION: Fortunately, our case had a favorable outcome compared to those reported in the literature with a median overall survival of 10 months, and up to 17 months in patients who receive stem cell transplant. In addition, following stem cell transplant, our patient achieved cure of his Crohn’s disease. A recent review of patients with immunoregulatory disorders who developed HSTCL noted that 56% of patients were treated with TNF-α inhibitors versus 89% with immunomodulators, indicating that the latter pose higher risk. To our knowledge, there have not been reports of HSTCL associated with vedolizumab use nor is there a known mechanism by which vedolizumab could cause HSTCL. In our case, TNF-α inhibitor was stopped 5 years prior and thiopurine analog 1 year prior to diagnosis, raising the question as to how long the risk of HSTCL remains elevated after cessation of such agents.