Treatment of refractory necrobiotic xanthogranulomas with extracorporeal photopheresis and intravenous immunoglobulin

Necrobiotic xanthogranuloma (NXG) is a disease of fibrotic or telangiectatic granulomatous papules and nodules that can ultimately progress into ulcerated plaques. Although the exact cause of NXG is unknown, it most often occurs in patients with paraproteinemia secondary to a hematologic disease. Consequently, therapy for NXG is targeted at treating the underlying hematologic disease, and subsequent paraproteinemia, with alkylating agents, antimetabolites, radiation, and/or immunosuppressive agents. Cases refractory to these therapies often have poor outcomes. We report the successful treatment of two patients with refractory NXG with two different modalities: extracorporeal photopheresis (ECP) and intravenous immunoglobulin (IVIG). The first case shows a patient without paraproteinemia who had success with ECP and IVIG, and the second is a patient with paraproteinemia treated effectively with IVIG. The beneficial response of our patients to IVIG, as well as ECP, shows that they may be an effective treatment option for refractory NXG.