Peptide-hormone- and serotonin-immunoreactive cells in normal and hyperplastic prostate glands.

Peptide-hormone- and serotonin-immunoreactive cells of endocrine type are present both in the normal prostatic gland and in the nodules of benign prostatic hyperplasia of man. They are located in the epithelium of the acini and the ducts of all the different parts of the gland, as well as in the urothelium of the prostatic part of the mucosa of the urethra. The endocrine cells are usually argyrophil, sometimes even argentaffin, and immunoreactive with neuron-specific enolase; they can be either of open or of closed type and usually occur widely scattered as single cells. Three kinds of endocrine cells were observed both in the normal gland and in the hyperplastic parenchyma. In the by far most prevalent type serotonin was found to co-exist with a peptide immunohistochemically related to the thyroid stimulating hormone (TSH). In a more rare type serotonin co-existed immunohistochemically with calcitonin. The third kind of endocrine cells was somatostatin-immunoreactive cells; they were also rather rare. The only difference observed between the normal and hyperplastic parenchyma was an increase in the number of all the three kinds of endocrine cells in the hyperplastic nodules. The endocrine cells could easily be visualized by means of silver-staining techniques, even using conventionally formalin-fixed, paraffin-embedded specimens.