1987 Volume 27 Issue 11 Pages 1104-1108
A 65-year-old woman had a 2 months' history of speech and gait disturbance. A precontrast computed tomography scan revealed a low-density mass in the left temporal region, which was irregularly enhanced after administration of contrast medium. A left carotid angiogram showed a shift of the middle cerebral arteries, but neither tumor staining nor feeding from the external carotid artery were observed. The extracerebral tumor in the left temporal region was removed, and the histological diagnosis was microcystic meningioma. Light microscopy revealed abundant microcysts throughout the tumor tissue, and electron microscopy disclosed that the microcysts were located in the extracellular spaces and not in the cytoplasm. It is possible that the microcysts simulate the formation of the subarachnoid space of the normal pia-arachnoid membrane and that, through their aggregation, the microcysts might form the macrocyst of the cystic meningioma.
