DISEASE CHARACTERISTICS: Histologically confirmed sarcomas in the following categories: Soft tissue sarcoma (STS) High-grade STS of the extremities Primary extending to fascia or locally recurrent At least 10 cm in greatest dimension or multifocal on surgical pathology Primary site controlled by surgery and/or radiotherapy High-grade truncal or head and neck sarcoma At least 10 cm in greatest dimension or any size with no surgical options for clear margins Primary site controlled by surgery and/or radiotherapy Locally recurrent disease in CR or PR after surgery, chemotherapy, or radiotherapy Metastatic STS in CR or PR after surgery, chemotherapy, or radiotherapy Osteosarcoma (OS) Extremity OS after neoadjuvant chemotherapy and surgical resection provided: Less than 50% necrosis in the surgical specimen LDH or alkaline phosphatase greater than 2 times normal at presentation Axial OS in CR or PR after chemotherapy and/or surgery Primary or recurrent metastatic OS in CR or PR after chemotherapy, surgery, and/or radiotherapy Ewing's sarcoma or primitive neuroectodermal tumor Primary site in CR or PR after chemotherapy, radiotherapy, or surgery Rib, pelvic, or axial skeleton primary Bulky tumor (at least 10 cm in greatest diameter) Primary or recurrent metastatic disease in CR or PR after surgery, chemotherapy, or radiotherapy Rhabdomyosarcoma Gross residual disease after primary treatment with surgery, chemotherapy, and radiotherapy Primary group IV or recurrent metastatic disease in CR or PR after chemotherapy and radiotherapy with or without surgery No brain metastasis No histologically confirmed bone marrow metastasis Prior metastases allowed with clearing of bone marrow at entry No contraindication to collection of mobilized stem cells or, if needed, autologous bone marrow