Intradiploic epidermoid tumor of the occipital bone: X-ray, CT, MR findings

Intradiploic epidermoid tumors are extremely uncommon. About 100 cases have been described in the literature [1]. It is thought that they are caused by inclusion of epitelial ectodermal cells in bone tissue during closure of the neural tube. Most of them are asymtomatic and usually detected when plain skull X-rays are made for other reasons. Others may be detected as a palpable lump. They can erode the inner table protuding into the brain. We report a case of an intradiploic epidermoid tumor of the occipital bone studied with plain skull X-rays, Computed tomography and magnetic resonance imaging. (orig.)