PATIENT CHARACTERISTICS: Age: Under 22 at diagnosis Performance status: Karnofsky 50-100% Life expectancy: At least 8 weeks Hematopoietic: See Disease Characteristics Hepatic: Bilirubin no greater than 1.5 mg/dL SGPT no greater than 2 times normal Renal: Creatinine normal OR Glomerular filtration rate at least 70 mL/min Cardiovascular: Shortening fraction at least 27% OR Ejection fraction greater than 50% No evidence of active cardiac disease by electrocardiogram Pulmonary: No evidence of active pulmonary disease by chest x-ray Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Neurologic deficits due to CNS disease must be stable within the past 4 weeks No active viral, bacterial, or invasive fungal infection No fever No prior hypersensitivity to interleukin-2 No greater than grade 2 mucosal toxicity