The significance of intraluminal crystalloids in benign prostatic glands on needle biopsy

Based on data from autopsy, radical prostatectomy, and cystoprostatectomy specimens, it has been suggested that the finding of intraluminal crystalloids in benign glands on needle biopsy may indicate a concurrent carcinoma; therefore, repeat biopsy is recommended. We studied data from 56 consecutive needle biopsies from the Johns Hopkins Hospital and Dianon Systems in which the diagnosis of intraluminal crystalloids in benign glands was rendered and follow-up data were subsequently obtained. Cases in which crystalloids were present in glands suspicious for cancer, in glands of high-grade prostatic intraepithelial neoplasia, or in adenosis were excluded from the study. Follow-up data included repeat biopsy results and serum prostatic specific antigen levels. Of the 56 men, 31 (55%) had repeat biopsy (two undervent transurethral resection of the prostate [TURP]); the remaining men were either noncompliant or had medical conditions precluding subsequent biopsy. Of the 31 men who underwent repeat biopsies, 23 (74%) had benign diagnoses, one (3%) had high-grade prostatic intraepithelial neoplasia, and seven (23%) had adenocarcinoma. There was no difference in serum prostate-specific antigen values between those with and without cancer on repeat biopsy. In a control population of men with a benign first biopsy not showing crystalloids, the incidence of cancer on repeat biopsy was 16.2%, which was not statistically significantly different from the incidence found in our study group. We conclude that men with prostate biopsy results showing benign glands with crystalloids are at no significantly higher risk of having cancer on repeat biopsy than if crystalloids were not present.