Subungual melanoma: a clinico-pathological study of 24 cases.

Twenty-four patients with subungual melanoma (13 women and 11 men) had a mean age of 61.6 years. Twenty-two lesions arose either on the thumb or hallux. The mean delay before diagnosis was 30 months. Two patients presented with stage two melanoma and three of the melanomas were in situ lesions (Clark level 1). Nineteen melanomas were Clark level 4 or 5 and the mean thickness of the invasive melanomas was 4.7 mm. Seven patients died of metastatic disease (mean survival 10 months, range 6-50 months). Clark level, thickness and mitotic activity of the melanomas correlated with poor clinical outcome. Delay in presentation and the presence of advanced disease contribute to the poor prognosis of this tumour.