DISEASE CHARACTERISTICS:

• One of the following diagnoses:

  • Newly diagnosed B-cell non-Hodgkin's lymphoma in Revised European-American Lymphoma (REAL) categories II 9, 10, and 11, i.e.:

    • Diffuse large cell
    • Burkitt's
    • High-grade B-cell, Burkitt's-like
  • L3 leukemia with greater than 5% blasts in bone marrow
• No anaplastic large cell Ki1-positive lymphomas
• Immunophenotype and Murphy stage required prior to randomization

PATIENT CHARACTERISTICS:

Age:

• Over 6 months to under 21 years

  • Maximum age 18 years in France and the United Kingdom

Other:

• No congenital immunodeficiency
• No prior organ transplantation
• No prior malignancy
• Not HIV positive
• Available for at least 36 months of follow-up

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior chemotherapy

Endocrine therapy:

• Steroids initiated no more than 72 hours prior to entry allowed

  • Bone marrow and cerebrospinal fluid examination required prior to steroids

Radiotherapy:

• Emergency radiotherapy initiated no more than 72 hours prior to entry allowed

Surgery:

• Not specified