Atypical and malignant intracranial meningiomas

Introduction. Meningiomas are one of the most common tumours of the central nervous system, with an incidence of 15% to 20% of all primary brain tumours. Meningiomas are generally slowly growing, benign tumours attached to the duramater and composed of neoplastic meningothelial cells. Most of meningiomas are benign and can be graded into WHO grade L However certain histological subtypes are associated with a poor clinical outcome and correspond to WHO grades II and III. Objective. To review the epidemiology, clinical, surgical, and histological aspects of multiple intracranial meningiomas. Patients and methods. The authors report 12 cases of malignant intracranial meningioma, consecutively operated on at our hospital between 1985-2002. All the patients were studied with CT and the last 9 with MRI. All patients showed no manifestations of von Recklinghausen disease. Results. The age at diagnosis ranged from 39 to 87 (mean 64.3 years). There were 6 males and 6 females. The predominant site for the meningioma was the parasagital region (5 cases), followed by the cerebral convexity (3 cases). All meningiomas were treated with surgical extirpation and in 8 cases the treatment was radiotherapy. The more common histological subtype was atypical meningiomas (5 cases). The median time survival was 48 months (range 16-168). Conclusions. Malignant meningiomas constitute 1% to 10% of all meningiomas. They affect men and women almost equally, in contrast, benign meningiomas are more commonly found in women. Complete surgical resection and administration of adjuvant irradiation following initial resection is crucial to long-term control.