Massive aneurysmal bone cyst of the anterior cranial fossa floor--case report.

A 19-year-old male patient presented with a midline facial, nose, and forehead hard and bony swelling associated with hypertelorism. Neuroimaging revealed a massive tumor involving the anterior cranial fossa floor, which had occupied and enlarged all paranasal air sinuses, and displaced the orbits outwards and the frontal lobes of the brain superiorly. A basal transcranial route was used for radical resection of the massive and vascular tumor. Histological examination confirmed an aneurysmal bone cyst. Such tumors only rarely involve the cranial bones or paranasal air sinuses.