Although the current radiological imaging is really performing, histologic examination remains essential in as much regarding the diagnosis as the pronostical assessment of cerebral tumors pronostic. The difficulties of histological diagnosis are not the same according to the various processes such as cerebral biopsy, extemporaneous examination or routine examination. Grading of gliomatous tumors is one among all the components that might enable pronostical assessment. Predictivity of meningiomas and pituitary adenomas recurrences remain unreliable despite numerous histological techniques that can be used (proliferative markers, bromodeoxyuridine incorporation, nucleolar organizers, flow cytometry).