DISEASE CHARACTERISTICS: Cutaneous melanoma in one of the following categories: T4, N0, M0 Deep primary tumor with Breslow depth greater than 4.0 cm Tx, N1, M0 Primary tumor with regional lymph node metastases found at lymphadenectomy but clinically undetectable Tx, N2, M0 Clinically apparent regional lymph node metastases (synchronous or metachronous) confirmed by lymphadenectomy Definitive surgical resection and lymphadenectomy with pathologically confirmed adequate surgical margins required Minimum 2 cm margin for primary lesions with Breslow depth greater than 2 mm Distal interphalangeal amputation required for subungual melanomas No primary melanoma originating apart from the skin No multiple in transit metastases in an extremity No lymph node involvement outside the operative area resected by radical neck, axillary lymph node, or ilioinguinal dissection