Combination Chemotherapy in Treating Young Patients With Langerhans Cell Histiocytosis

DISEASE CHARACTERISTICS: * Histopathologically confirmed diagnosis of Langerhans cell histiocytosis according to the criteria defined by the Histiocyte Society * Demonstration of CD1a antigenic determinants on the surface of lesional cells (by immunocytology or immunohistology) or Birbeck granules in lesional cells by electron microscopy * Considered at risk or low risk according to the following criteria: * Multi-system at risk disease, defined as involvement of one or more risk organs (i.e., hematopoietic system, liver, spleen, or lungs) * No single-system lung involvement * Multi-system low-risk disease * Multiple organs involved but without involvement of risk organs * Single-system disease * Multifocal bone disease (i.e., lesions in 2 or more different bones) * Localized special site involvement, such as CNS-risk lesions with intracranial soft tissue extension or vertebral lesions with intraspinal soft tissue extension * Vault lesions are not regarded as CNS-risk lesions PATIENT CHARACTERISTICS: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: * No prior treatment for Langerhans cell histiocytosis