Microvascularity in benign prostatic hyperplasia.

The vascular density of benign prostatic hyperplasia (BPH) has not been characterized. Previously we reported vessel density (vv/mm2) in prostatic carcinoma was twice that of normal prostate [Bigler et al.: Hum Pathol 24:220-226 1993]. To further characterize vessel density in benign prostate tissue we examined 15 cases of BPH obtained by open prostatectomy. Vessels were stained with antibodies to Factor VIII-related antigen, and vessel density was measured using computer-assisted image analysis. Vessel density was analyzed between various histologic tissue types. Mean vessel density in all transition zone tissue was 70.2 vv/mm2. Vessel density in epithelial hyperplastic nodules (mean 99.3, SD 40.7) exhibited density levels similar to those found in prostatic carcinoma (mean 101.4, SD 35.6). Vessel density in epithelial nodules was significantly higher than in non-nodular epithelial tissue (mean 76.7, SD 23.1; P < 0.001, ratio = 1.3). Higher vessel densities were found in hypercellular stromal nodules (mean 64.7, SD 19.1) than in adjacent stromal areas (mean 36.5, SD 15.3; P < 0.001, ratio = 1.8). Overall, vessel density in BPH was higher than previously found in benign tissue measured in radical prostatectomy specimens, especially in areas of nodular morphology.