What are the characteristics of a subungual melanoma?

Subungual lesions are often mistaken for a chronic inflammatory process; therefore, most patients present quite late. They are usually older than patients with other forms of cutaneous melanoma. The great toe is the most common site of origin. Amputation at or proximal to the metatarsal phalangeal joint and regional sentinel lymph node biopsy are advised by most authors. The primary lesions are usually deeply invasive, and the lymph nodes are positive for cancer in the majority of cases, either at the time of the original diagnosis or at subsequent follow-up.