Squamous carcinoma arising in a pilonidal sinus.

A patient with squamous cell carcinoma arising from an extensive pilonidal sinus was treated with wide local excision, resulting in an apparent cure over a 1-year follow-up period. Review of the literature revealed 32 previously reported cases of this entity. Forty-four percent of these patients developed recurrences or metastases, and 22% died of their disease. The largest historical treatment group with at least 1-year follow-up (19 patients with localized disease) underwent wide excision. Forty-two percent of these patients recurred or developed metastases. Ultimately, 89.5% of these patients were reported cured, but only five survivors were followed for as long as 5 years. Historical experience appears to identify pilonidal tract squamous carcinoma as an aggressive tumor. The reported success of wide local excision is based on a small number of patients followed for short periods of time. Continued experience with this disease should be reported to verify the adequacy of local excision or identify the need for adjunctive therapy.