OUTLINE: This is a dose escalation study of thiotepa. Patients receive cytoreduction and mobilization of peripheral blood stem cells (PBSC) with filgrastim (G-CSF) and cyclophosphamide/paclitaxel, cyclophosphamide/etoposide or cyclophosphamide/etoposide/cisplatin within 30-90 days of last dose of standard therapy. PBSC are then collected. Patients then receive melphalan IV over 30 minutes on days -6 and -5 and thiotepa IV over 2 hours on days -4 and -3. PBSC are reinfused on day 0. G-CSF is administered on days 0-21. Cohorts of 5-15 patients each receive escalating doses of thiotepa until the maximum tolerated dose (MTD) is reached. The MTD is determined as the dose at which 2-5 of 4-15 patients experience dose limiting toxicity. Patients are followed at 100 days, then at 6, 12, and 24 months.