Ultrastructural study of myoepithelial cells in breast carcinoma.

This investigation was designed to study the myoepithelium of the human mammary carcinoma. Tissues were obtained from 30 infiltrating ductal carcinomas. Under light microscope, there were no significant changes noted in the myoepithelium. Glutaraldehyde-fixed tissues were examined under electon microscope. In infiltrating carcinoma the myoepithelial cells contained increased endoplasmic reticulum, abundant microfilaments, secretory granules and intracytoplasmic duct formation. This observation suggests that myoepithelium takes an important and active role in the infiltrating stage of the human mammary carcinoma.