Iatrogenic intradiploic meningoencephalocele. Case report.

The authors present the case of a 6-year-old girl who developed a right frontal intradiploic meningoencephalocele following an accidental dural tear produced during surgery for craniosynostosis. Although rare, growing skull fractures have been described in at least eight cases following the accidental laceration of the dura mater in the course of craniosynostosis repair. These cases closely resemble those produced by accidental trauma to the growing skull. However, the intradiploic location of a meningoencephalocele following surgery for craniosynostosis has not been documented previously. This patient presented with headache and a frontal tumor of bonelike consistency. Radiographs and computerized tomography scans of the skull revealed an intraosseous cyst, whereas magnetic resonance imaging demonstrated cerebral tissue herniation within the intradiploic tumor. Surgical treatment consisted of duraplasty and cranioplasty, which achieved good functional and cosmetic results. The pathogenesis of this unusual lesion is discussed and compared with the hypotheses advanced for explaining posttraumatic intradiploic cysts.