MALIGNANT-MELANOMA OF THE TOENAIL APPARATUS

BACKGROUND: Subungual melanoma is an unpredictable and aggressive tumo r with a propensity to metastasize widely. Because it is an uncommon c ondition, statistical analysis of its behavior patterns is difficult, factors that determine its prognosis are unclear, and optimal manageme nt is ill defined. STUDY DESIGN: A detailed review was undertaken of t he clinical and histologic features of subungual melanomas arising fro m the toenail apparatus in 25 patients treated at the Sydney Melanoma Unit during a 40-year period. Treatment and outcomes were analyzed. RE SULTS: Most of the lesions were situated on the great toe in elderly p atients of Anglo-Celtic extraction. Antecedent trauma to the toe was f requently reported and delayed diagnosis was usual. There was great va riation in Breslow thickness and Clark's level, but these indices were found to have less prognostic significance than for other forms of cu taneous melanoma. CONCLUSIONS: The treatment of subungual melanoma of the toenail apparatus is primarily surgical, by amputation at or proxi mal to the metatarsophalangeal joint. Even if there is no clinical evi dence of metastatic disease in regional lymph nodes, radical node diss ection is desirable. The condition is most appropriately managed at a specialist center.