[Recurring intradiploic epidermoid cyst of the skull: a case report].

We report a case of a 65-year-old man with intradipolic epidermoid cyst of the frontal bone. The patient presented with headache and swelling of the forehead. Skull x-ray showed massive destruction of the frontal bone. Magnetic resonance imaging (MRI) revealed an epidural mass without any encroachment of the dura mater. The cystic tumor was removed followed by cranipolasty with methylmethacrylate. Four years later, the tumor recurred in the same region. At the second surgery the bony defect was again replaced with methylemthacrylate plate. Four years after the second operation, the tumor reemerged with some subcutaneous fluid retention. At the third surgery, the remaining tumor capsule was removed as much as possible except for that part which adhered to the superior sagittal sinus. The authors discuss the relationship of tumor recurrence with utilization of methylmethacrylate for cranioplasty in this type of tumor.