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