QUANTITATION OF THE PROSTATIC INTRAEPITHELIAL NEOPLASIA - ANALYSIS OF THE NUCLEOLAR SIZE, NUMBER AND LOCATION

Correlation has previously been demonstrated between qualitative and quantitative architectural and cytological features of the prostatic intra-epithelial neoplasia. In the present study, a standard Zeiss microscope and a horizontal eyepiece micrometer were used in an attempt to quatitatively define the size, number and location of nucleoli in relation to the degree of prostatic intra-epithelial neoplasia and associated benign prostatic hyperplasia and adenocarcinoma. In total, 20 prostatectomies, where features of benign prostatic hyperplasia (20 cases), prostatic intra-epithelial neoplasia of grade 1 (10 cases) and grade 2 (10 cases), and adenocarcinoma (20 cases) were present, were studied. The quantitative analysis showed that, going from benign prostatic hyperplasia to prostatic intra-epithelial neoplasia of grade 1 and 2, and to adenocarcinoma, the values of the size-related nucleolar features are progressively greater; when considering the frequency-related nucleolar features, the percentage of nucleolated nuclei increased sharply. This was associated with the decrease in the proportion of mononucleolated nuclei and increase in nuclei with two and three nucleoli. When considering the location-related nucleolar features, the degree of shift of the nucleoli to the periphery of the nucleus increased. Among all the quantitative features, the most evident changes in the nucleolar size were expressed by the nucleolar hypertrophy index after including in the calculation only those nucleoli with a diameter larger than 3 arbitrary units, whereas the percentage of nucleolated nuclei and the proportion of nuclei with two and three nucleoli best represented the modifications to the frequency. The shift in the nucleolar location in the nucleus was shown by the percentage of nucleoli in the peripheral position and by the nucleolar eccentricity index calculated after excluding nucleoli at the distance from the nucelar membrane greater than 2 or 3 Arbitrary Units. The nucleolar quantitative features can be considered useful in identifying the prostatic intra-epithelial neoplasia and in distinguishing two grades: low-grade and high-grade. The former is closer to benign prostatic hyperplasia, and the latter to adenocarcinoma.