Subungual squamous cell carcinoma of the toe: report on three cases.

BACKGROUND: Primary subungual squamous cell carcinoma (SCC) of the toe is seldom reported in the literature, with most described cases occurring on the fingernails. OBJECTIVE: To describe the clinical, histopathologic, and laboratory findings of cases of invasive subungual SCC of the toe. METHODS: All cases of SCC of the toes retrieved from our database in the last 3 years were reviewed. A search for human papillomavirus (HPV) DNA from paraffin-embedded sections was performed with polymerase chain reaction. RESULTS: Three patients, all male, with a subungual SCC (two well differentiated and one poorly differentiated) of the toe were identified. Treatment consisted of surgical amputation in all cases. One patient with poorly differentiated SCC and lymph node metastases also underwent inguinal lymphadenectomy. Polymerase chain reaction search for HPV DNA was negative in all samples. CONCLUSIONS: Unlike Bowen's disease and SCC of the fingernails, a causative role of HPV infection in the development of in situ and invasive subungual SCC of the toe seems unlikely.