Observation and/or Combination Chemotherapy After Surgery or Biopsy in Treating Young Patients With Extracranial Germ Cell Tumors

DISEASE CHARACTERISTICS: * Histologically\* proven extracranial malignant germ cell tumor (GCT), including mature/immature teratoma, with or without elevated alpha-fetoprotein (AFP) or human chorionic gonadotropin (HCG) levels * Newly diagnosed disease * Patients with relapsed or progressive extracranial malignant GCT allowed if previously treated with carboplatin, etoposide, and bleomycin (JEB) chemotherapy * Patients relapsing following JEB are eligible for the study relapse strategy NOTE: \*Patients with unequivocally raised AFP/HCG whose risk of biopsy is felt to be high can be diagnosed by clinical grounds, imaging, and markers * No intracranial GCTs PATIENT CHARACTERISTICS: * Neutrophil count ≥ 1,000/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Bilirubin ≤ 2 times upper limit of normal (ULN) * ALT ≤ 3 times ULN * Not pregnant or nursing PRIOR CONCURRENT THERAPY: * See Disease Characteristics * No prior chemotherapy other than JEB