[Participation of myoepithelial cells in the histogenesis of breast cancer].

The structural and functional features of myoepithelial cells of the intact mammary gland, dyshormonal dysplasias and parenchymatous elements of lobular carcinoma of this organ were studied and compared for the purpose of the elucidation of controversial issue of the role of myoepithelial cells in histogenesis of mammary gland carcinoma. Some distinctive histological (selective staining with amido black--tannin acid), enzyme-chemical (high adenosine-triphosphatase activity), and ultrastructural (cytoplasmic fibrils with focal consolidations, pinocytic vesicles) features of myoepithelial cells were determined. The detection of similar properties in parenchymatous elements of lobular carcinoma facilitated the determination of the tumor cytogenetic profile and suggested the myoepithelial origin of a certain part of carcinoma parenchyma.