Ki-67/MIB-1 immunostaining in a cohort of human gliomas.

Histopathological malignancy grading of human gliomas is limited by subjective interpretation of the morphological criteria. Assessment of mitotic activity is a cornerstone of grading these tumours, but mitotic figures can be hard to identify in haematoxylin-eosin stained sections. Thus, determining proliferative activity by means of Ki-67/MIB-1 immunostaining has become a useful supplement. However, this method has drawbacks, so continuous testing and evaluation are required for optimization and standardization. The aim of this study was to analyse and evaluate the Ki-67/MIB-1 proliferative indices (PIs) in a series of gliomas. We found that Ki-67/MIB-1 PIs correlated well with histological malignancy grade in all glioma subtypes, but a considerable overlap of PIs was observed between the malignancy groups. Consequently, Ki-67/MIB-1 immunostaining alone is not sufficient to adequately determine the malignancy grade. Therefore, future work is necessary to clarify the role of this immunostaining in the histopathological diagnosis of human gliomas.