Non-Langerhans cell histiocytosis with peripheral joint destruction and mediastinal lymph node invasion: The continuous feature spectrum of clinical multicentric reticulohistiocytosis and microscopical xanthoma disseminatum

The non-Langerhans cell histiocytoses (non-LCH) are rare and benign histiocytic disorders. We present a 61-year-old female with progressive skin-colored nodules on the face and extremities. The skin biopsy showed dermal infiltration of foamy histiocytes. Further imaging study showed erosive arthritis and lymphadenopathy. The microscopical feature of anterior mediastinal lymph node was similar to that in the skin. Thus, the diagnosis is non-LCH with joints and lymph nodes involvement. This patient presented both the clinical manifestations of multicentric reticulohistiocytosis (MRH) and histologic findings of xanthoma disseminatum (XD), indicating the plausible association and the shared disease spectrum of MRH and XD.