Prostatic Intraepithelial Neoplasia in Transurethral Resection Specimens On serum PSA and histologic findings

ABSTRACT

Prostatic intraepithelial neoplasia (PIN), which is divided into low and high grade, has different clinicopathologic significance. We reviewed 158 prostatic tissues, which consisted of 144 cases of nodular hyperplasias and 14 cases of adenocarcinomas, to evaluate incidence of PIN, its histologic finding, and its clinical significance. Ten cases of PIN, 4 low grade and 6 high grade, were found. Four cases of low grade PIN (LPIN) and five cases of high grade PIN (HPIN) were associated with nodular hyperplasia. Only one case of HPIN occurred in carcinoma. The constant histologic findings of LPIN were nuclear stratification and nucleomegaly. The most prominent characteristics of HPIN were hyperchromasia and prominent nucleoli. Anisonucleosis was not so helpful for differential diagnosis between LPIN and HPIN. Basal layer disruption was present in one case of high grade PIN associated with adenocarcinoma, and important for the differentiatial diagnosis of cribriform HPIN from the cribriform adenocarcinoma. There was no significant difference in age incidence between the two groups with the mean age of 70.9 years in nodular hyperplasia and 69.4 years in adenocarcinoma. Serum PSA level was significantly different between the two group with the mean PSA value of 11.03 ng/ml in nodular hyperplasia and that of 73.76 ng/ml in carcinoma (p=0.000). However, PSA values between "nodular hyperplasia only" group and "PIN associated nodular hyperplasia" group were not significantly different. PIN association changed neither age distribution nor serum PSA level. During the follow up period, no adenocacinoma has occurred in the cases having PIN although serum PSA level has elevated in some cases. One case of adenocarcinoma associated with HPIN developed in the nodular hyperplasia patient. Although PIN did not increase the possibility of subsequent prostatic adenocarcinoma in transurethral resection specimens, it could not be excluded that PIN was a precursor of prostatic adenocarcinoma.