Wu J.-H.MENG-YAO LUKAI-HSIN LINSHIANN-TANG JOUDONG-TSAMN LIN2020-12-162020-12-1619990001-6578https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033491242&partnerID=40&md5=fbdc8ee5b39b22df985d05cbc5d408f6https://scholars.lib.ntu.edu.tw/handle/123456789/526488Langerhans cell histiocytosis (LCH) is a group of poorly understood disorders. To our knowledge, LCH is a non-malignant disorder. The association of LCH with a secondary neoplasm has not been well assessed, however, a few cases have been reported. We report a case of LCH, a localized osteolytic lesion over metaphysis of left femur, who was treated with local curettage and chemotherapy with vincristine, prednislone and 6-mercaptopurine (6-MP) for eight months from end of 1991 to August, 1992. Six years later, she had acute lymphoblastic leukemia (ALL) in 1998. In review of current literature, only 5 cases of LCH, including our case, have preceded ALL. The possible association, a reactive process or a therapy-related process, between LCH and acute leukemia is still unclear at present and needs to be explored by more studies in the future.[SDGs]SDG3mercaptopurine; prednisolone; vincristine; acute lymphoblastic leukemia; article; case report; child; curettage; disease association; drug induced cancer; drug safety; female; histiocytosis X; human; preschool child; second cancer; Female; Histiocytosis, Langerhans-Cell; Humans; Infant; Leukemia, Lymphocytic, Acute, L1journal article109279612-s2.0-0033491242