DISEASE CHARACTERISTICS: Histologically proven primary melanoma with extensive regional node metastases (T1-4, N1, M0) OR Primary melanoma with clinically apparent metastases confirmed by lymphadenectomy (T1-4, N1-2, M0) OR Clinically detected relapse of melanoma in regional node basin, confirmed by lymphadenectomy after prior management of primary site (T1-4, N1-2, M0) OR Recurrence of melanoma in a nodal basin previously resected OR Nodal metastatic melanoma arising from unknown primary, confirmed by lymphadenectomy (Tx, N1-2, M0) Adenopathy from neck, axilla, or groin basins must meet one of the following criteria: At least 4 positive nodes containing tumor Nodal metastases at least 3 cm in size Gross extracapsular extension of tumor Recurrence after prior lymphadenectomy Completely resected disease No distant metastases