Prognostic value of Ki67: comparison of the proliferation index between meningiomas with and without infiltration of glial tissue.

ABSTRACT

BACKGROUND: Although generally considered benign, meningiomas can cause significant morbidity and mortality.  Histologic grade is the most useful morphologic predictor of recurrence. OBJECTIVES: To compare Ki67 labeling index between meningioma grade I and meningioma grade II with brain invasion. METHODS: We analyzed 20 primary meningioma, 10 of which were grade I and 10 of which were grade II. Ki67 proliferative indices were determined in all cases. RESULTS: The patient population consisted of 9 males and 11 females with mean age of 60 years. For meningioma grade I, the Ki67 labeling index varied between 1 and 15% with an average of 3.1%. A diagnosis of gradeII meningiomas was made solely on the basis of brain invasion. The immunohistochemical study noted that the Ki67 index varied between 1 and 20% with an average of 6,8%. CONCLUSION: The Ki67 labeling index shows a significant increase from grade I to grade II.  It may provide useful prognostic information.