Malignant melanoma with unknown primary site.

From 1955 to 1976, 129 patients were seen with metastatic malignant melanoma from an unknown primary site, comprising 8.1% of all the referred patients with malignant melanoma. Eighty-two percent of the patients presented with a history of mass or lump. Overall median survival and 5-year survival rates after onset of symptoms were 10 months and 13%, respectively. Patients with lesions of the head and neck area had 5-year disease-free survival of 25%, whereas those with lymph node disease had a survival of 18%. Twenty-nine patients with regional disease had wide excision (usually lymphadenectomy) and their 5-year disease-free survival was 58%. Regional disease in patients with malignant melanoma of unknown primary site should be treated with radical surgical excision, since the survival is comparable or better to that of patients with regional disease having known and excised primary site.