Atypical meningioma: clinicopathological analysis of a new WHO classification

ABSTRACT

The World Health Organization [WHO] reclassified atypical meningiomas in 2000, creating a more clear and broadly accepted definition. We evaluated the pathological and clinical management for atypical meningioma patients according to the new WHO grading system at Cairo University Hospital. A total of 30 atypical meningiomas occurring in 30 patients between 2005 and 2007 were prospectively reviewed to determine diagnosis, postoperative treatment trends and early outcomes. In the 3-year period, 371 meningiomas were operated on at Cairo University Hospital; of these, 320 [86.5%] were benign, 30 [8%] atypical and 21 [5.6%] malignant. The histological parameters permit an accurate identification of atypical and malignant meningiomas with high growth potential and recurrence rates that far exceed that of benign meningiomas. We hope that the use of these relatively simple histological criteria will help to further the understanding of the biology of this important group of tumours