Endocrine-paracrine cells of the prostate and prostatic urethra: an ultrastructural study.

A remarkable morphologic diversity among the endocrine-paracrine (EP) cells of the prostate and prostatic urethra was found in this study. Based on granule morphology, a wide variety of EP cell "types" was discerned, although many intermediate and mixed cells, forming a continuum, were also observed. The EP cells were of both the open (containing luminal borders) and closed types. The latter often had long dendritic processes. Prominent lamellar bodies, possibly representing a form of crinophagy, were present in some EP cells. The variety and morphologic complexity of these prostatic and urethral EP cells suggest that they play an important role in both normal and pathologic conditions.