Comparison of Ki67 and modified AgNOR in dysplastic epithelial lesion, primary squamous cell carcinoma and metastatic squamous cell carcinoma of head and neck

The variations in nucleolar organizer regions (AgNOR) and the increase in Ki67 expression and correlation with histological findings in 64 specimen squamous epithelium from normal epithelium to overt carcinoma were evaluated. Mean AgNOR counts (mAgNOR), proliferative index (pAgNOR), variation in size and dispersion of AgNOR dots in cells were graded and compared in normal, dysplastic, primary and metastatic squamous cell carcinoma (SCC). The Ki67 percentage is significantly increased from normal squamous to SCC group, and the reactivity of staining were related to histological differentiation. The mAgNOR counts were high in all 44 cases of primary and metastatic SCC and low in normal squamous tissue and increased in dysplastic lesions. The mAgNOR count in SCC increased from well differentiated to poorly differentiated. PAgNOR counts were gradually increased in different grade of SCC, 1.4% in well differentiated, 6% in moderately differentiated, 19% in poorly differentiated. There was only significant difference between well differentiated versus poorly differentiated cases. Only significant correlation between Ki67 percentage and mAgNOR and between Ki67 percentage and pAgNOR in primary SCC group was noticed. Therefore, Ki67 is gold standard method for evaluation of proliferation activity. AgNOR quantity is proportional to the proliferative activity of the cell but does not necessarily indicate malignancy.