Frontal sagittal meningioma: tumor parasitization of cortical vasculature as the etiology of peritumoral edema. Case report.

Peritumoral edema surrounding meningiomas is poorly understood; however, several theories have been proposed in the literature. A case is presented here of a frontal sagittal meningioma symmetrically effacing both frontal lobes that subsequently evokes peritumoral edema on only one side. The tumor is histologically identical on the left and right sides. Angiograms were obtained that support previous work, which suggests that the degree of cortical parasitization of blood supply correlates with peritumoral edema whether or not tumor secretory factors are involved.