A Benign Rare Lesion of the Breast: Giant Epidermal Inclusion Cyst.

An epidermal inclusion cyst can be seen at any location. Epidermal cysts are commonly found on the scalp, face, trunk, neck, and extremities. They are rarely seen in the breast parenchyma. These benign lesions are important in that they may undergo neoplastic differentiation, although very rarely. Epidermoid cysts usually develop as a result of the implantation of superficial epidermal tissue into the dermis or subcutaneous tissue after trauma or surgical procedures. In this study, a 37-year-old female patient who underwent a histopathological examination that showed a 10-cm epidermal cyst without a history of trauma or a surgical procedure was discussed.