Study Type: Interventional

Study Design:

Endpoint Classification: Efficacy Study Intervention Model: Single Group Assignment Masking: Open Label Primary Purpose: Treatment purpose: This single arm clinical trial is studying efficacy and tolerance of combination chemotherapy with methotrexate and cytosine arabinoside in newly diagnosed adult with Langerhans cell histiocytosis.

This single arm clinical trial is studying efficacy and tolerance of combination chemotherapy with methotrexate and cytosine arabinoside in newly diagnosed adult with Langerhans cell histiocytosis.

Inclusion Criteria:

1.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)

    1.No single-system lung involvement

  • Multi-system low-risk disease

    1.Multiple organs involved but without involvement of risk organs

  • Single-system disease 1.Multifocal bone disease (i.e., lesions in 2 or more different bones) 2.Localized special site involvement, such as CNS-risk lesions with intracranial soft tissue extension or vertebral lesions with intraspinal soft tissue extension 3.Vault lesions are not regarded as CNS-risk lesions 2.PATIENT CHARACTERISTICS:

    1. Not pregnant or nursing
    2. Negative pregnancy test
    3. Fertile patients must use effective contraception 3.PRIOR CONCURRENT THERAPY:
    1. No prior treatment for Langerhans cell histiocytosis

Exclusion Criteria: