Acute promyelocytic leukaemia in a patient treated with etoposide for Langerhans cell histiocytosis.

We report a child with acute promyelocytic leukaemia (APL) who was treated with etoposide (VP16) for Langerhans cell histiocytosis (LCH). A 3-year-old Japanese girl was diagnosed as having LCH. She was treated with combination chemotherapy using VP16 and prednisolone. 56 months after beginning the chemotherapy she developed APL. Her bone marrow was occupied with atypical promyelocytes including giant granules and multiple Auer bodies. A cytogenetic analysis of the leukaemic cells showed 46,XX,11p-,14q+,t(15,17). The cumulative dose of the administered VP16 was 12,120 mg/m2, which suggested that VP16 may be responsible for the development of APL. The risk of developing secondary leukaemia after the administration of VP16 should therefore be considered when managing patients with LCH.