Meningiomas account for approximately one-third of primary central nervous system tumors (table 1 and figure 1). Most meningiomas are benign (WHO grade I), although up to one-third of such tumors are classified as atypical (World Health Organization [WHO] grade II) or malignant (WHO grade III). (See "Meningioma: Epidemiology, risk factors, and pathology", section on 'Pathology'.)
The management of patients with meningioma requires a balance between definitive treatment of the tumor and avoidance of neurologic damage from the treatment. Patient-specific factors (eg, presence or absence of symptoms, age, comorbidity), the location of the meningioma in relation to critical brain structures and regions, and the histopathologic characteristics (WHO grade) of the meningioma all are important factors in determining the optimal treatment.
WHO grade II and grade III meningiomas will be reviewed here. Other topics on meningioma include:
Meningiomas are classified according to the World Health Organization (WHO) schema, which is based upon strict morphologic criteria . The current version of the WHO classification system was promulgated in 2007. This system divides meningiomas into three groups, based upon morphologic criteria, and has been shown to correlate with prognosis and thus has important implications for patient management (table 2).