LIGHT AND ELECTRON MICROSCOPIC STUDIES ON HUMAN BLADDER CACINOMAS

Relationship between Structure and Differentiation of Cancer Cells

Abstract

Biopsied tumor tissues of 23 cases of human bladder carcinomas were histologically and electron-microscopically investigated. The majority of well-differentiated papillary transitional cell carcinomas (Grade I and II) revealed the surface tumor cells accompanied by large granule, degenerative vacuoles and pseudoadenomatous lumina in their surfaces. The well-differentiated cancer cells showed electron-microscopically the various cytoplasmic organelles such as mitochodria, tight junction, desmosomes, endoplasmic reticulum Golgi apparatus and lysosomes.
On the other hand, squamous and glandular metaplastic foci, disappearance of surface tumor cells and an increase of dark cells and exfoliation of tumor cells were observed in poor-differentiated cancers (Grade III and IV). The poor-differentiated cancer cells showed eletron-microscopically a decrease of various cytoplasmic organelles, especially tight junction, desmosome and mitochondria, and an increase of free ribosomes and microvillous cytoplasmic protrusions and intercellular spaces.
The quantity of glycogen and cytoplasmic fibrile of tumor cells were seemed not to be proportional to differentiation of cancer. In the squamous metaplastic foci in bladder cancers were electron-microscopically observed an increase of tonofibrile, desmosome and tonofilament desmosome complex. However, it was unable to identify the presence of typical keratohyalin granules in these foci.
Discussion was also briefly made on the genesis of dark cell, lymphoid reaction in cancer stroma and the direction of tumor growth.