No abstract

Normal fetal and newborn prostates were studied to evaluate growth patterns, histogenesis, and secretory activity. Whole cross-sectioned prostates harvested from 107 necropsies of fetuses and newborns ages 20 weeks gestation to 1 month of age were used. Development of the prostate occurred in three stages: bud stage (20-30 weeks gestation), bud-tubule stage (31-36 weeks gestation), and acinotubular stage (37-42 weeks gestation). Squamous metaplasia often appeared in the urethra, utricle, and primary lobular ducts, and occasional microcysts were noted. PAS and alcian blue-PAS positive secretion were present in 65% of the specimens by 20-30 weeks gestation and in over 87% of the specimens by 37 or more weeks gestation. Secretory activity was most prominent in the lateral regions of the peripheral zone. Prostate-specific antigen was only weakly detected throughout the prenatal period and was not related to secretory activity as evidenced by the PAS technique.

The goal of this study is to characterize stromal nodules in benign prostatic hyperplasia (BPH) in a Chinese population. BPH specimens were obtained by superpubic enucleation. Immunohistochemical staining for vimentin, muscle actin (HHF35), and smooth muscle actin (1A4) was conducted in serial sections of 55 consecutive stromal nodules of BPH specimens. The simplest stromal nodules were undifferentiated nodules that contained vimentin-negative and smooth muscle actin-negative cells. These cells were designated as undifferentiated mesenchymal cells. Immunohistochem-ical staining identified two cell types. Smooth muscle cells contained smooth muscle actin and vimentin, while fibrocytes contained vimentin but not smooth muscle actin. Fibrous nodules contained fibrocytes. Two more types of stromal nodules were fibromuscular nodules, which contained mixtures of fibrocytes and smooth muscle cells, and muscular nodules, which contained only smooth muscle cells. Of 55 stromal nodules, 11 (20%) were undifferentiated, 5 (9%) were fibrous, 37 (67%) were fibromuscular, and 2 (4%) were muscular.