Meningiomas are common tumors of the central nervous system that originate from the meningeal coverings of the brain and the spinal cord. Many factors are involved in tumor progression,one of the important factors is mutation of tumor suppressor gene p53. Ki-67 is considered to be the most reliable proliferative marker predicting tumor behavior.The aim of the present study is to evaluate the use ofimmunhistochemical expression of p53 and ki67 for predicting the grades of meningioma which are important in their prognosis.Sixty patients with different grades of meningioma were taken. Histological sections of the paraffin embedded tissues of these cases were be taken for H&E staining for assessment of histological grade according to WHO grading system. Immunohistochemical staining of sections of the paraffin embedded tissues by using monoclonal antibody for P53 & ki-67 were done. Correlation between tumor grades and immunhistochemical markers were done.The presences of mitosis,sheeting,prominent nucleoli,hypercellularity,pleomorphism,and the necrosis,except brain invasion,were correlated with tumor grades. The mean Ki-67 labeling index was significantly higher in meningiomas of WHO grade III than in those of grades I and II. Overexpression of p53 was found mainly in the atypical and malignant meningioma group. There is a good and positive correlation between Ki-67 and p53 expression.The Ki-67 proliferative marker and p53 are both presented highly in atypical and malignant meningioma,the routine use of them in predicting the behavior of meningiomas may be advocated based on the results of this study.
Immunohistochemical Detection of Proliferative Marker Ki-67 in Benign and Malignant Salivary Gland Tumors