MIB1 and meningioma: The present study investigated the role of the Simpson grade system, meningioma location and grade in the risk of recurrence, and aimed to assess the proliferative index in a series of surgically removed meningiomas using immunohistochemical methods with immunohistochemical marker (MIB-1) labeling indices (LI) associating this index with clinical, radiological and histological factors.