Caption |
Ductal carcinoma in situ: this photomicrograph illustrates the morphology of an interlobular duct that is distended by neoplastic cells. Neoplastic cells have not ruptured the basement membrane of the interlobular mammary duct. Numerous neoplastic cells undergo apoptosis. A few mitoses are noted. Also, at the center of the duct, there is a small cluster of large cells (arrowheads) with better defined cell borders and a more hypochromatic than nearby cells. These features are consistent with squamous metaplasia. Myoepithelial differentiation (arrow) is present. |