A rare case: a large perianal epidermal cyst Perianal epidermal cyst is a rare entity. A 44 year old male presented with perianal swelling which was progressively increasing in size. Pelvic tomography revealed a 7 cm cystic tumor. The tumor was excised totally and pathological diagnosis was epidermal cyst. To our knowledge, here we report the eleventh case of perianal epidermal cyst.