Quantitative evaluation of PCNA and AgNORs expression in ameloblastomas

Abstract

In order to assess the proliferative behaviour of the ameloblastoma epithelium nine cases of this neoplasm were retrieved from the files of the Oral Pathology Service laboratory of Rio Grande do Sul Federal University School of Dentistry. Two proliferation marker techniques were employed: the AgNor - argyrophilic nucleolar organizer regions staining and the proliferation cell nuclear antigen (PCNA) immunohistochemical assessment technique. Each case was submitted to a quantitative and comparative statistical analysis of the results obtained for the two techniques. The conclusion arrived at shows ameloblastoma presenting benign behavior, an average AgNOR index of 1.612, and a PCNA proteindependent proliferative activity with average immunoreactivity of 51.61%. The histological patterns analyses of the neoplastic epithelial component demonstrates that cells resembling pre-ameloblasts have obtained figures statistically higher to those obtained for cells resembling the stellate reticulum of the enamel organ, in both techniques employed. Therefore, it might be inferred that cells resembling pre-ameloblasts hold the proliferative potential of ameloblastomas and are probably responsible for the growth characteristics and infiltrative ability of this tumour.