PRIOR CONCURRENT THERAPY: Biologic therapy: At least 12 months since interferon alfa or melanoma vaccine No prior immunotherapy for metastatic disease No concurrent cytokines or levamisole Chemotherapy: No prior chemotherapy for metastatic disease At least 4 months since adjuvant therapy No concurrent chemotherapy Endocrine therapy: At least 1 week since corticosteroids No concurrent immunosuppressives (e.g., azathioprine or cyclosporine) Radiotherapy: Prior radiotherapy for metastatic disease allowed Surgery: See Disease Characteristics Prior surgery for metastatic disease allowed