Elektronenmikroskopische Untersuchungen zur Zelldifferenzierung in Prostata-Carcinomen

Abstract

20 confirmed human prostatic carcinomas of various histological types were studied by electron microscopy. As a result of the ultrastructural findings it was possible to define characteristic cell types which are normally present in prostatic carcinomas irrespective of their histological differentiation. As these cell types are frequently situated side by side, the prostatic carcinoma acquires a characteristic variegated appearance. Three main cell types can be distinguished. 1. A cell with a pale, euchromatic, round nucleus, very prominent nucleolus, and a narrow layer of bright cytoplasm with few organelles. This cell shows no secretory activity and has to be classified as a poorly differentiated or embryonic cell. It may be assumed that these cells have a high proliferative activity. 2. A cell with dark, pleomorphic, heterochromatic nucleus and a broad layer of dark cytoplasm containing numerous organelles. This cell type is apparently functionally stimulated and active. The disproportionate increase and arrangement of the organelles, however, makes it morphologically atypical: These alterations seem to result from an irregular process of enzyme synthesis and secretion. 3. A vacuolated cell: this cell has a dark, pyknotic nucleus and a broad layer of subtotally vacuolated cytoplasm. Probably it refers to a nonfunctional, hypersecretory and degenerative tumour cell. Transitional cell forms are not unusual. Sometimes carcinoma cells are visible in tumourous glands, and are so highly developed and well differentiated that the ultrastructural findings by themselves give no answer in the question of malignancy. Basal cells were seen in five of the carcinomas investigated, mainly in tumours with cribriform or solid patterns. The cytoplasm of these cells shows few organelles. Bundles of cytoplasmatic filaments are often present. It is uncertain whether these cells are of myoepithelial type. The knowledge of the described cell variants will be of clinicopathological importance if therapeutic effects on prostatic carcinoma are estimated cytomorphologically at the ultrastructural level.