Cystic intracranial meningioma.

Between April 1983 and April 1991, we studied nine cases of intracranial meningioma with cystic change out of 100 intracranial meningioma patients. The incidence was 9%. The patient's ages ranged from 40 years to 75 years old. There were five men and four women, of them, three had intratumoral cysts, and six had peritumoral cysts. Histologically, 7 cases were diagnosed as meningothelimatous type, one as psammomatous and the other one as angioblastic type. All the tumors with cystic change in this series were greater than two centimeters in diameter. Because the morphology was indistinct, Nauta's type II cystic meningioma was easily misdiagnosed as glioma or metastatic tumors preoperatively. Microsurgery is the best way for complete removal of the cyst wall to prevent recurrence.