Perineal epidermal cyst.

This paper presents a case of perineal epidermal cyst. Diagnostic imagings by ultrasonography, CT scanning and MR imaging described the mass as a cystic tumor on the perineal median raphe. It was excised for the histological diagnosis. The removed mass was shown microscopically to be filled with laminated keratin and to be lined with differentiated cornified squamous epithelium. The pathological diagnosis was benign perineal epidermal cyst.