Mechanism of formation of the psammoma bodies in serous adenocarcinomas of the ovaries

: Histological and electron microscopic examinations of 7 serous adenocarcinomas of the ovaries permitted to follow all the stages of psammous body formation starting from the submicroscopic level. The formation of psammous bodies was shown to be connected with a relatively differentiated epithelium of the adenocarcinomas. Initially, microcrystals of oxyapatites are deposed on accumulations of protein substances in ergastoplasm cysterns and on mitochondrial cristae. With further accumulation of these crystals relatively large intracytoplasmic inclusions of oxyapatites are formed which after confluence fill the cell which results in its death. In this way a small psammous body becomes free-lying.