Ultrastructure of the secretion of prostasomes from benign and malignant epithelial cells in the prostate.

Background: Prostate epithelial cells are producing, among other things, a fluid secretion containing small bodies, the prostasomes. The mechanism of synthesis of the prostasomes is not known in details, neither is it known whether the mode of prostasome production changes at a neoplastic transformation of the prostate cells. Due to the small size of the prostasomes, we have used electron microscopy for evaluating the production and distribution of prostasomes in benign and neoplastic cells of the prostate.

Methods: Benign and neoplastic areas in plastic embedded core biopsy specimens of prostate tissue were identified, and secreting cells were selected. The corresponding areas on the plastic blocks were further processed for examination in the electron microscope.

Results: The electron microscopical examination showed that the secretory machinery was similar in both types of tissue. Thus, in both benign and well-differentiated neoplastic cells studied, the formation of storage vesicles in the Golgi areas was similar, the content of the vesicles appeared similar, the structure and distribution of prostasomes were alike, and in both benign and malignant tissue, the secretion in the gland ducts showed the same appearance with many prostasomes.

Conclusion: We conclude that cells in benign prostate tissue and cells in well-differentiated prostate carcinoma show great similarities in synthesis, storage, and release of prostasomes. However, this does not exclude the presence of other changes, for instance biochemical ones, in the prostasomes.