Abstract
Epidermoid cysts are slowly growing pseudotumors usually measuring <2 cm in diameter. Large epidermoid cysts invading bones have been rarely reported in the literature. They may be a source of diagnostic difficulties before pathological analyses, and radiological examinations are essential to determine the extension of the cyst and to guide the surgical technique. We report, herein, on a patient having an unusually large epidermoid cyst located in the left occipital area invading the occipital bone.