Atypical meningioma: a study of prognostic factors.

Objective: Atypical meningiomas represent 20% of all meningiomas. This retrospective study analyzes the prognostic factors, the effect of different methods of treatments, and the behavior of atypical meningiomas.

Methods: The study comprised 44 patients who were given a diagnosis of atypical meningioma according to the 2007 World Health Organization classification in the period from January 2009 to March 2012.