Atypical and malignant meningiomas: an outcome report of seventeen cases.

Abstract

Limited data are available concerning the outcome of patients with atypical and malignant meningiomas. We therefore analyzed the outcome of seventeen patients with meningiomas (9 atypical; 8 malignant) at Thomas Jefferson University Hospital between 1973 and 1996. Strict adherence to the 1993 WHO criteria for the typing of CNS tumors was maintained. The median potential follow-up period for all patients was 87 months. The age at diagnosis ranged from 22 to 72 (mean 51.8 years). There were 5 males and 12 females. The mean tumor diameter was 4.45 cm. Of the 16 cases where the extent of surgical resection was known, 4 were partial and 12 were complete resections. Six patients (35%) had dural or cortical invasion by tumor. Fifteen patients received postoperative megavoltage photon irradiation (mean 61 Gy). One of these fifteen pts. received an additional 20 Gy with Au-198 implantation and 1 received post-radiation chemotherapy for recurrent disease. The overall survival rate for all patients at 5 and 10 years were 87% and 58% respectively. The 5- and 10-year survival rates for atypical meningiomas were 87% and 58%; for malignant meningiomas the survival rates were 60% and 60% respectively. Five patients (30%) have died. Three of these 5 patients initially received less than 54 Gy to the tumor bed and have died of recurrent disease. Local disease progression was documented in 11 patients (65%) after surgery and in 3 patients (18%) after radiation. There was an improvement in performance status in 3 (18%) patients with a decline and no change seen in 1 (6%) and 13 (77%) respectively after receiving radiation. There appeared to be no difference in survival in patients as a function of dural or cortical invasion. Long term survival is possible for patients with atypical and malignant meningiomas treated with surgery and post-operative radiation. We are unable to distinguish a difference in outcome between these two pathological entities. Dural and cortical invasion were not associated with a decrease in survival. In addition, improved tumor control and survival may be associated with increased radiation dose.