Successful treatment of a case of acute myeloid leukemia following Langerhans cell histiocytosis in an adolescent: a case report and review of the literature.

Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder of unknown etiopathogenesis. Its clinical presentation is variable and ranges from isolated skin or bone disease to a life-threatening multisystem condition. LCH can occur at any age but is more frequent in the pediatric population. The diagnosis depends on clinical, histopathological and radiographic examination and should be confirmed by immunohistochemical study with CD1a, S100 protein and langerin, three markers used widely for identifying Langerhans cells. Herein, we report an adolescent with acute myeloid leukemia (AML-M2) who was treated just with surgical management alone for LCH. As far as we know, this is the first case that the LCH patient without chemotherapy evolved into AML and was successfully cured. Cooperative studies of large numbers of LCH patients are needed to evaluate a possible association between LCH and acute leukemia, and to identify common risk factors or predisposing agents if such be present. The previously reported cases of LCH concomitant with other hematological disorders are also summarized and described compared with the present case.