Squamous cell carcinoma of the nail apparatus: clinicopathological study of 35 cases.

Background: Subungual squamous cell carcinoma (SCC) is rare. Its diagnosis is often missed or delayed because the clinical presentation is often atypical and can mimic other conditions such as verruca vulgaris, onychomycosis, trauma-induced nail dystrophy or exostosis.

Objectives: To define the different clinical presentations and the main pathological features and to evaluate the most appropriate surgical management of subungual SCC.

Methods: A retrospective review of all the cases of subungual SCC seen in our institution over a 5-year period.

Results: Thirty-five cases were selected. The spectrum of the clinical features encountered was extremely large including leuconychia, subungual hyperkeratosis, trachonychia, subungual tumoral syndrome, longitudinal erythronychia and melanonychia. Most cases (31 of 35) were invasive. Relapse rate after surgical treatment was low after wide surgical excision (5%) of the nail apparatus or amputation of the digit. However, limited surgical excision led to more frequent relapses (56%).

Conclusions: Nail apparatus SCC is often misdiagnosed. Most cases are invasive at the time of diagnosis. Wide surgical excision bears a lower risk of relapse. Micrographic surgery should be considered for a better control in cases treated with limited surgical excision.