Lymph node metastasis from melanoma with an unknown primary site.

Twenty-six patients, treated surgically between 1961 and 1986 because of lymph node metastasis from melanoma with an unknown primary, were analysed. Six patients had a history of spontaneous regression of a skin lesion. Following node dissection, the overall actuarial disease-free survival rate was 49 per cent, after both 5 and 10 years. When considered as single factors, female (versus male), one lymph node involved (versus more than one node involved) and site of metastasis in the groin or axilla (versus the neck) were found to have significantly favourable effects on prognosis with 5-year survival rates of 82 per cent (25 per cent), 82 per cent (27 per cent) and 80 per cent (11 per cent) respectively. However, at multifactorial analysis only the site of cervical metastases maintained a significant influence on survival (P = 0.005). As survival in this series is comparable with, or even better than, that of adequately treated patients with lymph node metastasis from a known primary melanoma, a radical node dissection is essential also in these patients.