Normal histology of the prostate.

The prostate gland contains three major glandular regions--the peripheral zone, the central zone, and the transition zone--which differ histologically and biologically. The central zone is relatively resistant to carcinoma and other disease; the transition zone is the main site of origin of prostate hyperplasia. There are also several important nonglandular regions concentrated in the anteromedial portion of the gland. Each glandular zone has specific architectural and stromal features. In all zones, both ducts and acini are lined by secretory epithelium. In each zone, there is a layer of basal cells beneath the secretory lining, as well as interspersed endocrine-paracrine cells. Frequent deviations from normal histology include post-inflammatory atrophy, basal cell hyperplasia, benign nodular hyperplasia, atypical adenomatous hyperplasia, and duct-acinar dysplasia. These lesions may at times be confused with carcinoma, especially in biopsy material.