Long Term Clinical Outcomes of Malignant Meningiomas

Objective: Malignant meningiomas are rare and have worse prognosis than benign meningiomas. We report our experience of a malignant meningioma and review relevant literature in an attempt to investigate the clinical features, treatment, and prognosis of these tumors.

Methods: Fifteen patients underwent surgical treatment for intracranial malignant meningiomas between year 1990 and 2012 in our institution. Anaplastic meningiomas were diagnosed in thirteen cases and papillary meningiomas in two. Fourteen patients (93.3%) received radiotherapy after surgical resection. All patients were followed regularly including clinical-neurological follow-up as well as magnetic resonance imaging. Progression was determined radiographically when there was more than 10% of mass volume increase or when there were onset or worsening of neurological symptoms not attributable to other causes.

Results: Six patients were male and nine were women, and their mean age was 56.9 years (range 36-78). The median follow-up was 54 months (range 3-246). According to our study result, the 5-year progression free survival rate of malignant meningiomas was 53.6%. There were 2 cases (13.3%) of postoperative complications. Recurrences were confirmed in 4 patients (26.7%) during follow-up, the median recurrence time was 35 months (range 12-61), and further procedures were performed. Two of the recurred patients were treated with radiosurgery after secondary tumor resection, and other two patients were treated with radiosurgery alone. There was no more recurred disease patients in the follow-up period after then.

Conclusion: We report the outcomes of the aggressive surgery with radiation of malignant meningiomas. Although the data is limited, we found that radiosurgery treatment had favorable tumor control on recurred patients from our experience.