Development of germinoma during the treatment of systemic-onset juvenile idiopathic arthritis with infliximab.

We report a 19-year-old patient with systemic-onset juvenile idiopathic arthritis (JIA) who developed a mediastinal germinoma during treatment with infliximab. Although the cancer risk of infliximab is controversial, this agent may have accelerated the growth of the germinoma. We conclude that the indications for tumor necrosis factor (TNF) inhibitors should be strictly decided and that a nationwide cohort study is necessary to assess the risk of cancer in patients with JIA exposed to biologics.