Langerhans cell histiocytosis in a child while in remission for acute lymphocytic leukemia

The occurrence of Langerhans cell histiocytosis (LCH) and malignancy in the same patient is rare. When LCH occurs concomitantly with acute leukemia, distinct temporal patterns often exist; acute myelogenous leukemia (AML) typically succeeds LCH, whereas acute lymphocytic leukemia (ALL) usually precedes it. We report a case of LCH developing in a child while in remission for ALL. Unique features of this case include the disseminated nature of the LCH and the death of the patient from LCH rather than ALL.