Meningiomas: Overview and New Directions in Therapy

Nancy Wang, MD; Matthias Osswald, MD


Semin Neurol. 2018;38(1):112-120. 

In This Article


Meningiomas are graded from I to III based on histological criteria established by the World Health Organization (WHO) grading system (Table 1), which thus far does not take molecular and genetic information into account. WHO grade I tumors are classified as benign, but there is significant heterogeneity within this grade, with recurrence rates ranging from 7 to 25%.[2,25] For the diagnosis of atypical (WHO grade II) meningiomas, the 2016 WHO classification now includes brain invasion as a histological criterion, even in the absence of additional histological features. The overall recurrence rate for atypical meningiomas is 29 to 52%, with a higher rate in those exhibiting high mitotic activity and pseudopalisading micronecrosis.[2,26] Anaplastic (malignant) WHO grade III meningiomas have the highest recurrence rates (50–94%) as well as higher rates of brain invasion and metastasis. In the future, a deoxyribonucleic acid (DNA) methylation-based meningioma classification may be incorporated into meningioma classification.[27]