DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor at original diagnosis
• Refractory to conventional therapy and other therapies of higher priority according to the COG Phase I/II priority list or no conventional therapy exists
• No primary CNS tumors or known metastases to the CNS

PATIENT CHARACTERISTICS:

Age:

• Under 22

Performance status:

• Karnofsky 50-100% (over 10 years of age) OR
• Lansky 50-100% (10 years of age and under)

Life expectancy:

• At least 8 weeks

Hematopoietic:

• Absolute neutrophil count at least 1,000/mm^3
• Platelet count at least 50,000/mm^3 (transfusion independent)
• Hemoglobin at least 8.0 g/dL (RBC transfusion allowed)

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• ALT no greater than 3 times ULN
• Albumin at least 2 g/dL

Renal:

• Creatinine normal for age OR
• Glomerular filtration rate at least 70 mL/min

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No uncontrolled infection

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 6 months since prior allogeneic stem cell transplantation (SCT)

  • No evidence of active graft-versus-host disease
• At least 1 week since prior biologic agents
• At least 1 week since prior hematopoietic growth factors
• Recovered from prior immunotherapy

Chemotherapy:

• At least 2 weeks since prior myelosuppressive chemotherapy (4 weeks for nitrosoureas) and recovered

Endocrine therapy:

• No concurrent tamoxifen

Radiotherapy:

• At least 2 weeks since prior local palliative (small port) radiotherapy
• At least 6 months since prior craniospinal radiotherapy or radiotherapy to 50% or more of the pelvis (6 weeks for radiotherapy to other substantial amount of bone marrow)
• Recovered from prior radiotherapy

Surgery:

• Not specified

Other:

• No concurrent drugs with known corneal toxicity (e.g., chlorpromazine, amiodarone, or chloroquine)
• No concurrent enzyme-activating anticonvulsants
• No concurrent proton pump inhibitors or H_2 blockers within 4 hours of gefitinib administration