Immunohistochemical demonstration of cytokeratins in the human prostate

The behaviour of keratins in the human prostate is investigated immunohistochemically by polyclonal rabbit antibodies against keratins from human stratum corneum (kit from ORTHO/Heidelberg) and compared to the behaviour of prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA). In normal glands and cribriform as well as adenomatous hyperplasia only basal cells contain keratin. The secretory epithelium is keratin-negative and in contrast to the basal cells PAP- as well as PSA-positive. In prostatic ducts and utriculus prostaticus keratin is demonstrable in basal cells and urothelium. As in normal glands, the light cylindric epithelium is keratin-negative and PAP- as well as PSA-positive. The cells in atrophic glands and postatrophic hyperplasia may contain keratin as well as PAP and PSA. Urothelial and squamous metaplasia are strongly keratin-positive. PAP and PSA are not found. The cylindric epithelium of the ejaculatory ducts contains keratin at many places. PAP and PSA are not demonstrable. The utriculus does not differ from normal prostatic glands immunohistochemically. This supports the view that the epithelium of the sinus urogenitalis is involved in the embryogenesis of normal prostatic glands and the utriculus as well. Urothelial and squamous metaplasia obviously arise from basal cells which share the same immunohistochemical features. Whether the cells in atrophic glands and postatrophic hyperplasia derive from basal cells or secretory epithelium cannot be decided. The keratin composition of the prostate should be further analyzed by keratin-specific monoclonal antibodies.