Combination Chemotherapy Followed by Bone Marrow Transplantation in Treating Patients With Rare Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed malignancy of one of the following types: * Wilms' tumor * Liver cancer * Desmoplastic or other small round cell tumor * Nasopharyngeal carcinoma * Fibrosarcoma * Disease that has metastasized and has a cure rate of no greater than 25% with conventional treatment or disease that has progressed after prior chemotherapy, was not then surgically resectable, and has a salvage rate with nonmyeloablative therapies of no greater than 25% required * Maximal benefit from conventional (nonmyeloablative) doses of combination chemotherapy required prior to entry, and it is recommended that patients have received a minimum of one of the following: * 2 courses of high-dose cyclophosphamide (as per protocol MSKCC-90062) * 2 courses of high-dose ifosfamide/etoposide (as in the poor-risk sarcoma protocol MSKCC-90071A) * 1 course of high-dose cyclophosphamide plus 1 course of high-dose ifosfamide/etoposide * Within 3 weeks of initiation of protocol therapy, patients must be: * In CR or good PR OR * Tumor considered "chemosensitive", i.e., a 50% or greater decrease in at least 1 measurable tumor parameter attributable to prior chemotherapy without evidence of progressive disease by any other parameter * Ineligible for other IRB-approved myeloablative regimens * No evidence of current bone marrow involvement on bone marrow aspiration (x4) and biopsy (x2) PATIENT CHARACTERISTICS: Age: * 21 and under Performance status…