Luminal contents of benign and malignant prostatic glands: Correspondence to altered secretary mechanisms

Recent changes in tissue fixation strategy, using glutaraldehyde, have clar ified the secretory mechanisms of the normal prostate identifying cytoplasm ic prostatic secretory granules, structures not preserved by formalin fixat ion. This normal secretory mechanism was absent in most adenocarcinomas, de picting an important metabolic change in transformed prostate cells. The cu rrent study further investigates differences between benign and malignant p rostate secretion and relates them to the production of corpora amylacea by benign glands and crystalloids or mucin by cancer. In all normal prostate cells examined (6 cases), prostate secretory granules (PSG) were approximat ely 1-mu m, brightly eosinophilic granules filling the cytoplasm of secreto ry cells and released in packets by a specialized apocrine cell structure. After apocrine decapitation and luminal dispersal, some of the cytoplasmic and PSG remnants condensed to form eosinophilic bodies (EB) with a glycopro tein rim and central protein core. EB were observed adsorbing and layering onto the surface of prostatic corpora amylacea representing their chief mod e of enlargement. Biochemical analysis and x-ray diffraction studies confir med sulfated glycosaminoglycans of similar structure as the main constituen t of both PSG and corpora amylacea. Peripheral zone amphiphilic "dark cell" carcinoma (9 cases) contained almost no PSG, and showed neither apical dec apitation nor EB formation, but mucin secretion was frequently detected. Cr ystalloids that share the same staining characteristics and sulfur content as PSG and corpora amylacea were identified in 3 selected "clear cell" carc inomas, all of which showed at least focal PSG secretion. The recognition o f these differing secretory mechanisms and their deviation from normal furt her defines the histological criteria and spectrum of prostate malignancy H UM PATHOL 31:91-100. Copyright (C) 2000 by W.B. Saunders Company.