DISEASE CHARACTERISTICS:

• Histologically confirmed diagnosis of solid tumor or leukemia with documented M3 marrow

  • Histologic confirmation of intrinsic brain stem tumors not required
• Relapsed or refractory disease
• No known curative therapy
• In patients with CNS tumors, neurologic deficits must be stable for at least the past week

PATIENT CHARACTERISTICS:

Age

• 1 to 21

Performance status

• Karnofsky 50-100% (>10 years of age)
• Lansky 50-100% (≤ 10 years of age)

Life expectancy

• Not specified

Hematopoietic

• For patients with solid tumors:

  • Absolute neutrophil count ≥ 1,000/mm^3
  • Platelet count ≥ 100,000/mm^3 (transfusion independent)
  • Hemoglobin ≥ 8.0 g/dL (may receive RBC transfusions)

• For patients with leukemia:

  • Platelet count ≥ 20,000/mm^3 (may receive platelet transfusions)
  • Hemoglobin ≥ 8.0 g/dL (may receive RBC transfusions)

Hepatic

• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• ALT ≤ 2.5 times ULN
• Albumin ≥ 2 g/dL

Renal

• Creatinine clearance OR radioisotope glomerular filtration rate ≥ 70 mL/min OR

• Creatinine based on age as follows:

  • ≤ 0.8 mg/dL if ≤ 5 years of age
  • ≤ 1.0 mg/dL if > 5 years and ≤ 10 years of age
  • ≤ 1.2 mg/dL if > 10 years and ≤ 15 years of age
  • ≤ 1.5 mg/dL if > 15 years and ≤ 21 years of age

Other

• No uncontrolled infection
• No prior severe allergy to eggs
• No situation that would preclude study participation
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• At least 7 days (or window for adverse effects has passed) since prior biologic therapy and recovered
• At least 7 days since prior hematopoietic growth factors
• At least 2 months since prior stem cell transplantation and no evidence of graft-vs-host disease
• No concurrent hematopoietic growth factors
• No concurrent biologic therapy
• No concurrent immunotherapy

Chemotherapy

• At least 3 weeks since prior myelosuppressive chemotherapy (6 weeks for nitrosoureas) and recovered
• No other concurrent chemotherapy

Endocrine therapy

• No concurrent steroid therapy

Radiotherapy

• At least 2 weeks since prior local palliative radiotherapy (small port)
• At least 3 months since prior total body irradiation or craniospinal radiotherapy
• At least 3 months since prior radiotherapy to ≥ 50% of the pelvis
• At least 6 weeks since prior substantial bone marrow radiotherapy
• Recovered from prior radiotherapy
• No concurrent radiotherapy

Surgery

• Not specified

Other

• No other concurrent investigational drugs
• No other concurrent anticancer agents
• No concurrent phenytoin or phenobarbital
• No concurrent warfarin