Objectives. To examine the significance of high-grade prostatic intraepithelial neoplasia (HGPIN) in biopsy specimens.

Methods. We performed sextant biopsies on a series of 83 cystoprostatectomy specimens removed for bladder cancer. For each case the number of foci and volume of both HGPIN and prostate cancer were assessed in the prostatectomy specimens and compared with the number of biopsy specimens involved by HGPIN.

Results. We identified HGPIN in 82 (99%) of 83 prostatic glands, whereas prostate cancer was found in 41 cases (49%). Corresponding sextant biopsies harbored both HGPIN and prostate cancer in 6 cases (7%), whereas only HGPIN was diagnosed in 29 sextant biopsies (35%). There was a positive correlation between the number of biopsy specimens containing HGPIN and the volume and multifocality of HGPIN in the corresponding prostatic glands. Prostates with HGPIN on sextant biopsy contained prostate cancer significantly more often when compared to cases with no HGPIN on sextant biopsy. Frequency of concurrent prostate cancer was higher in cases with two or more biopsy specimens containing HGPIN than in cases with only one such biopsy specimen, but case numbers of these categories were too small to render this difference statistically significant.

Conclusions. The presence of HGPIN in sextant biopsies is a significant predictor of concurrent prostate cancer. Multifocality of HGPIN is a useful parameter in assessing the extent of HGPIN in the corresponding prostates. Its value in predicting a significantly increased risk of concurrent prostate cancer needs to be further investigated in larger case studies.