title: Occurrence of acute nonlymphoblastic leukemia in two girls after treatment of recurrent, disseminated Langerhans cell histiocytosis.
abstract: The occurrence of Langerhans cell histiocytosis (LCH) and acute leukemia in one individual has rarely been observed. Despite few exceptions, two distinct patterns of association appear evident: acute lymphoblastic leukemia preceding LCH and LCH preceding acute nonlymphoblastic leukemia (ANLL). The latency of ANLL after the diagnosis of LCH is suggestive of a therapy-related process. This report describes two new cases in whom ANLL was diagnosed 7 years 8 months and 5 years 8 months after the start of initial treatment of disseminated recurrent LCH. Morphology showed blasts from FAB-type M4/M5 in the first patient, who died due to progression of leukemia. The second patient showed myelodysplastic syndrome (refractory anemia with excess of blasts in transformation; RAEB-t) and is now in remission from leukemia 3 years 11 months after allogeneic bone marrow transplantation. The review of a total of 26 patients with ANLL after LCH suggests that the disease has a poor prognosis and allogeneic BMT seems to be the treatment of choice.
mesh_terms: D016026:Bone Marrow Transplantation; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000209:etiology* / Q000628:therapy; D012008:Recurrence