Multimodality treatment of squamous cell carcinoma complicating pilonidal disease.

Malignant degeneration is an unusual complication of chronic primary or recurrent pilonidal disease. To date, only 43 cases have been reported, the great majority being squamous cell type. Historically, these cases were treated with primary excision. Recurrence following such treatment was high and prognosis poor compared with nonmelanoma skin cancer. We describe a patient with squamous cell carcinoma arising in chronic pilonidal disease, who is disease-free 3 years after adjuvant radiation therapy following radical excision. This communication describes the clinicopathologic features of 38 cases of squamous cell carcinoma arising in pilonidal disease and suggests treatment modalities.