Should the diagnosis of benign prostatic hyperplasia be made on prostate needle biopsy?

Abstract

Pathologists frequently sign out benign prostate needle biopsies as "benign prostatic hyperplasia (BPH)". There are no data indicating that a diagnosis of BPH on biopsy correlates with either gland weight or with the International Prostate Symptom Score (IPSS) used to measure urinary obstructive symptoms. We examined biopsies for average percentage of glands and average percentage of glands with papillary infolding per case, maximum percentage of glands and maximum percentage of glands with papillary infolding per core per case, and presence of any stromal nodules per case. BPH was measured in 2 ways: (1) IPSS grouped into 3 categories (mild, moderate, severe) and (2) prostate weight at radical prostatectomy in men with limited cancer. IPSS was classified as follows: mild (n = 12), moderate (n = 13), and severe (n = 10). There was no correlation with IPSS and any of the histologic features measured. For the 41 radical prostatectomy specimens, the average weight was 65.3 g (median, 56.0 g, range, 22 to 117 g). There was no correlation between gland weight and the average or maximum percentage of glands, or average or maximum percentage of glands with papillary infolding. Stromal nodules on biopsy correlated with gland weight. In the 30 cases without stromal nodules on biopsy, the mean gland weight was 51.4 g. In the 11 cases with stromal nodules on biopsy, the mean gland weight was 77.4 g (P = 0.0125). However, stromal nodules were not specific for a large prostate (i.e., a 15 g prostate had stromal nodules on biopsy). With the exception of stromal nodules found on biopsy, histologic findings on biopsy are not specific for either clinical or pathologic BPH. Thus benign prostate biopsies should be signed out merely as "benign prostate tissue."