OUTLINE: Patients with complete response proceed to further therapy according to age. 65 and under: Patients receive etoposide by IV continuously for 5 days, cytarabine IV over 2 hours every 12 hours for 4 days, and filgrastim (G-CSF) subcutaneously. Peripheral blood stem cells (PBSC) are then harvested. Patients then receive oral busulfan every 6 hours on days -7 to -4 and etoposide IV over 10 hours on day -3. PBSC are reinfused on day 0. Over 65: Patients receive oral isotretinoin and vitamin E daily. Treatment continues in the absence of disease progression or unacceptable toxicity. Patients are followed every month for 1 year and then every 3 months thereafter.