Unknown primary melanoma.

Of 230 melanoma patients treated during the past 8 years, 12 (5.2%) were found to have unknown primary lesions. Nine of these "unknown primary melanoma' patients presented with metastases in regional lymph nodes, one inside the parotid gland, and two presented with disseminated melanoma and no detectable primary tumor. The patients with melanoma confined to a regional lymph node underwent block dissection followed by adjuvant chemotherapy and immunotherapy. Four patients with metastasis in only one lymph node are disease free 4-6 years after diagnosis. One patient with multiple metastases in the groin is alive 8 years after lymphadenectomy. The other five patients with metastases in multiple regional lymph node died 16 months to 3 years after surgery. Both patients with disseminated melanoma succumbed to their disease within a month of diagnosis. The prognosis of unknown primary melanoma seems to be no worse than the typical melanoma at the same stage. This justifies the aggressive surgical approach to this unusual entity of melanoma.