DISEASE CHARACTERISTICS: Diagnosis of peripheral primitive neuroectodermal tumor, including peripheral neuroepithelioma or Askin tumor OR Diagnosis of localized or metastatic Ewing's sarcoma, including the following: Unresectable or metastatic small cell osteosarcoma Unresectable or metastatic other nonrhabdomyosarcomatous soft-tissue sarcomas Unresectable or metastatic other non-osteosarcomatous bone sarcomas Desmoplastic small round-cell tumor Metastatic or non-metastatic Wilms' tumor Immunocytochemistry, electron microscopy, and/or chromosomal analysis may be required to rule out other small round cell neoplasms