Purpose: We attempted to identify morphological parameters of benign prostatic hyperplastic inflammation that correlate with pre-biopsy prostate specific antigen (PSA) concentrations.
Materials and methods: Patients undergoing prostate biopsy at our department were prospectively studied between January 1995 and January 1996. preoperative blood and 24-hour urine samples were measured for PSA. Biopsy samples harboring exclusively benign prostatic tissue were graded on a 4-point scale for inflammation (0-no inflammatory cells, 1-scattered inflammatory cell infiltrate, 2-nonconfluent lymphoid nodules and 3-large inflammatory areas with confluence of infiltrate) and aggressiveness (0-no contact between inflammatory cells and glandular epithelium; 1-contact between inflammatory cell infiltrate and glandular epithelium; 2-clear but limited, that is less than 25% of the examined material, glandular epithelium disruption, and 3-glandular epithelium disruption on more than 25% of the examined material).
Results: A total of 66 patients with exclusively benign prostatic tissue on prostate biopsies was analyzed. Difference between inflammation graded groups was not significant when considering serum or urinary PSA. There was a significant correlation between aggressiveness grading and serum PSA (rho = 0.51, p < 0.0001), whereas aggressiveness grading and urinary PSA did not correlate (rho = -0.06, p = 0.6).
Conclusions: Prostatic subclinical inflammation is not associated with high urinary PSA. Unless associated with glandular epithelial disruption, density of prostatic interstitial inflammatory cell infiltrate is not significantly correlated with serum PSA concentration. We believe that this issue should be considered when interpreting a prostate biopsy.