Meningioma pathophysiology

Pathogenesis
Meningiomas arise from arachnoidal cells, most of which are near the vicinity of the venous sinuses, and this is the site of greatest prevalence for meningioma formation. They are most frequently attached to the dura over the superior parasagittal surface of frontal and parietal lobes, along the sphenoid ridge, in the olfactory grooves, the sylvian region, superior cerebellum along the falx cerebri, cerebellopontine angle, and the spinal cord. The tumor is usually gray, well-circumscribed, and takes on the form of space it occupies. They are usually dome-shaped, with the base lying on the dura.

Histologically, the cells are relatively uniform, with a tendency to encircle one another, forming whorls and psammoma bodies (laminated calcific concretions). They have a tendency to calcify and are highly vascularized.