Treatment of unknown primary melanoma.

Sixty-four patients with unknown primary melanoma were identified among 1045 new patients with melanoma (6%) seen during an 11-year period. Their mean age was 44.5 years (median age, 42.7 years). Of these, 39 (59%) were men, and 25 (38%) were women. In 34, only one site was involved. Common single sites were the axilla (29%), groin (24%), and neck (32%). Most of the melanomas (88%) were melanotic. Patients with localized melanoma surgically treated (n = 34) had a median survival of 53 months, and a 5-year survival rate of 45%. The respective rates for disseminated melanoma were 7 months and 10% (P = 0.00001). Localized, unknown primary melanoma should be treated with radical excision because a substantial proportion of patients so treated survive 5 years.