Preoperative planning for meningioma. There is an enhancing mass with prominent flow voids that appears to arise from the anterior falx cerebri, which measures up to 64 mm. There is an associated peritumor cyst or trapped cerebrospinal fluid collection that measures up to 14 mm along the left aspect of the tumor, as well as a similar 4 mm wide focus along the right aspect of the tumor. There is considerable mass effect upon the adjacent brain, as well as vasogenic edema in the regional brain parenchyma, left greater than right. However, there may be superimposed mild ischemic changes in the medial left frontal lobe. There is also effacement of the bilateral lateral ventricle frontal horns, but dilatation of the more posterior portions of the right lateral ventricle. There is posterior and right lateral displacement of the bilateral anterior cerebral arteries. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
A large vascular mass that appears to arise from the anterior falx cerebri with associated peritumor cysts and mass effect upon the adjacent brain, as well as extensive vasogenic edema, is compatible with a meningioma. The posterior portions of the right lateral ventricle appear to contain entrapped cerebrospinal fluid.