Diffuse calvarial meningioma. Case report and review of the literature.

An extremely unusual calvarial meningioma in a 77-year-old woman is reported. The meningioma spread widely and symmetrically within the calvaria and grew extracranially within the scalp as well as intracranially. Reactive dural hyperplasia induced narrowing of the intracranial space and occlusion of the superior sagittal sinus, resulting in intracranial hypertension. After external decompression, the patient's symptoms markedly resolved. The authors review the literature on calvarial meningioma, discuss its pathogenesis, and propose mechanisms responsible for the patient's intracranial hypertension.