[Parasagittal meningioma with unusual venous drainage manifesting through peritumoral hemorrhage. Case report].

A 63-year-old female was admitted with a 5-day history of left hemiparesis. Computed tomography showed an enhanced mass with perifocal edema in the right frontal parasagittal region and an irregular-shaped, high-density mass anterior to the tumor. Right carotid angiography disclosed the prominent middle meningeal artery (MMA) to be the main feeding vessel of the tumor. In the venous phase, the superior sagittal sinus (SSS) was obstructed and a dilated middle meningeal vein (MMV) drained downward to the sphenoparietal sinus. Left carotid angiography demonstrated similar findings. There was a filling defect in the lumen of the MMV due to the MMA running within the vein. At surgery, careful manipulation was required, as the venous blood in the left MMV drained not only from the tumor but also from the anterior half of the SSS. The left MMA was found to run through the cavity of the dilated MMV. The SSS was invaded by tumor. There was an old hematoma cavity containing xanthochromic fluid in the brain parenchyma adjacent to the tumor. Histological examination showed meningothelial meningioma. The postoperative course was uneventful, although the right MMV was opacified on carotid angiography. It was suspected that obstruction of the SSS by tumor invasion had caused dilatation of the bilateral MMV and peritumoral hemorrhage due to disturbance of the venous drainage.