Abstract
In 1983, a 67-year-old male was hospitalized because of headache, left hemiparesis, and numbness. He underwent craniotomy and fluid aspiration on three occasions. On readmission in 1985, plain computed tomography (CT) scan revealed a round, hypodense mass in the right parietooccipital region, which was markedly enhanced on contrast CT. Angiography showed a tumor stain fed by the right angular artery. The preoperative diagnosis was glial tumor. At surgery the tumor was found to adhere to the dura in the right parieto-occipital convexity, and intra and peritumoral cysts were observed. Microscopic examination of a tumor specimen disclosed both intra and extracellular vacuolization and microcysts. The histological diagnosis was vacuolated meningioma with cyst formation. Seventeen cases of vacuolated or microcystic meningiomas have been reported, and two salient features have been identified: a high rate of cyst formation and distinctive CT findings of hypodensity on plain scans and marked enhancement on contrast scans. It is speculated that vacuoles fuse to form microcysts and that further fusion eventually results in the formation of macrocysts.
