Eruptive agminated nevi in a successfully treated Langerhans cell histiocytosis patient.

A 7-year-old girl with a history of Langerhans cell histiocytosis (LCH), in remission, presented with the sudden appearance of multiple, agminated nevi. Skin biopsy revealed a benign junctional nevus, without recurrence of LCH. Subsequent immunohistochemical testing of both the skin and iliac wing biopsies demonstrated a BRAF V600E mutation. MAPK pathway mutations have been implicated in both LCH and nevogenesis.