Peritumoral brain edema and cortical damage by meningioma.

Forty supratentorial meningiomas were analyzed to identify factors causing peritumoral brain edema. Parasagittal, sphenoid ridge, and olfactory groove meningiomas induced edema more frequently than those in other locations. Meningothelial meningiomas were more invasive than other types and were associated with more peritumoral edema. Brain edema correlated significantly with tumor size and histological evidence of leptomeningeal and cortical damage from the tumor. Larger tumors destroy the leptomeninges and cerebral cortex, allowing direct transmission of edema fluid into the white matter, resulting in vasogenic edema.