gms | German Medical Science

Objective: In 2007 the criteria for WHO classification of meningiomas were modified. Meningiomas with infiltration of the brain but with a histopathologically benign appearance were further classified as atypical meningiomas according to WHO grade II (WHO II). A rising incidence of meningiomas WHO II was therefore expected. The aim of our investigation was to examine the incidence of meningiomas with special regard to the WHO grade before and after modification of the classification system in our series.

Method: A retrospective chart review of patients with intracranial meningioma, who were treated in our department between 2003 and 2011 was performed. Histopathological examination was assessed by an experienced neuropathologist.

Results: A total of 522 patients with histologically proven intracranial meningiomas were included. Histological grading was as follows: WHO I, n=464 (88.8%); WHO II, n=55 (10.5%); WHO III, n=3 (0.57%). The median age of all patients was 61 years (range 6-93 years). M:F ratio of all patients was 1:3. In patients treated between 2003 and 2007 the numbers were as followed: n=260 (49,8%) WHO I, n=38 (69,1%) WHO II, no meningioma WHO III. In patients treated between 2008 and 20011 the numbers were as followed: n=262 (50,2%) WHO I, n=17 (30,9%) WHO II, n=3 (100%) WHO III. Over the years the number of meningiomas WHO II was distributed as follows: n=8 in 2003, n=9 in 2004, n=5 in 2005, n=7 in 2006, n=9 in 2007, n=6 in 2008, n=4 in 2009, n=6 in 2010, n=1 in 2011.

Conclusions: Between 2003 and 2011, a total of 522 patients with intracranial meningiomas were treated in our department. Since the last modification of the criteria for WHO classification of meningioma in 2007, a higher incidence for meningiomas WHO II could not be documented in this series.