Aneurysmal bone cyst involving the skull base: report of three cases.

Aneurysmal bone cyst is a bening, non-neoplastic lesion that present most frequently under the age of 20 years. The metaphysis of long bones is the usual site of origin. The involvement of the skull is rare. In the 2.5 to 6% of such cases reported in the literature, the skull vault is more often the site than the skull base. Three cases of aneurysmal bone cyst involving the skull base have been managed at King Faisal Specialist Hospital and Research Center. Two females and one male, all 10 years of age and younger, presented with a painless, progressive swelling. The preoperative radiological studies showed characteristic findings and were highly suggestive of the diagnosis. Angiography also gave characteristic findings. Preoperative endovascular embolization of the arterial feeders to the tumor was performed in two patients who had a significant decrease in intraoperative bleeding from the tumor. All cases underwent surgical excision with a good outcome.