Lymphoma in Pediatric-Onset Inflammatory Bowel Disease Treated with Infliximab Monotherapy: A Case Series

Inflammatory bowel diseases (IBD) are often treated with anti-tumor necrosis factor alpha (anti-TNFα) medications. Concomitant treatment of IBD with anti-TNFα agents and immunomodulators appears to be associated with an increased risk for lymphoma. Patients who developed lymphoma while on monotherapy with an anti-TNFα agent were identified at three centers. Institutional Review Board approval was obtained. Five adolescents and young adult patients with pediatric-onset IBD who were treated with infliximab (IFX) without exposure to thiopurines were subsequently diagnosed with lymphoma. Three of the five patients had bone involvement at presentation. Epstein–Barr virus was positive in 2 cases. Median time from diagnosis of IBD and exposure to IFX prior to diagnosis of lymphoma was 5 and 4.3 years, respectively. This case series reports long-term follow-up for young patients with IBD who were treated with IFX monotherapy and developed lymphoma. Three of the five patients had bone involvement. In general, the risk of lymphoma following exposure to anti-TNFα medications alone remains low, but the incidence of primary bone lymphomas in IBD has not been reported. Studies examining longer exposure times may be needed to determine the true lymphoma risk in patients treated with IFX monotherapy.