Langerhans cell histiocytosis following childhood acute lymphoblastic leukemia

Langerhans cell histiocytosis (LCH) is a clonal proliferation of Langerhans cells of unknown etiology that results in a range of clinical manifestations. LCH has been known to be associated with a variety of malignant diseases. A 7-year-old boy was treated for standard-risk acute lymphoblastic leukemia (ALL) at age 2 years, on a Children's Cancer Group chemotherapy protocol for 3 years and developed LCH 2 years after completion of chemotherapy. The case and a review of literature on the association of LCH and ALL are presented.