Interferon Alfa-2b With or Without Radiation Therapy in Treating Patients With Melanoma That Has Metastasized to Lymph Nodes in the Neck, Under the Arm, or in the Groin

DISEASE CHARACTERISTICS: Histologically documented malignant melanoma in node(s) meeting one or more of the following criteria: 1 or more lymph nodes found to contain metastatic melanoma with gross evidence of extracapsular nodal extension Nodal recurrence at the site of previous lymphadenectomy All gross cancer removed with negative margins Prior node biopsy allowed if complete nodal dissection performed Parotid involvement outside a node allowed No distant metastases PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-1 Life expectancy: Not specified Hematopoietic: WBC at least 4,000/mm3 Platelet count at least 125,000/mm3 Hematocrit at least 33% Hepatic: AST no greater than 2 times upper limit of normal (ULN) LDH no greater than 2 times ULN Alkaline phosphatase no greater than 2 times ULN Bilirubin no greater than 2 times ULN If LDH or alkaline phosphatase are above normal, CT or MRI of liver required Renal: Creatinine no greater than 1.8 mg/dL BUN no greater than 33 mg/dL Other: Not pregnant or nursing Fertile patients must use effective contraception No other prior or concurrent malignancies within 2 years, except any carcinoma in situ, lobular carcinoma of the breast in situ, carcinoma in situ of the cervix, atypical melanocytic hyperplasia or Clark I melanoma in situ, or basal or squamous cell skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy: No prior interferon Chemotherapy: Not specified Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy to the head and neck, axillary, or inguinal areas Surgery: See Disease Characteristics Recovered from prior surgery