Caption |
Mammary gland: the neoplasm is predominantly composed of bundles and fascicles separated by a scant amount of fibrovascular stroma. A few epithelial areas characterized by the formation of small nests and trabeculae persist at the periphery of the neoplasm and there is gradual transition between the epithelial and the mesenchymal phenotype. Cells with an epithelial phenotype are polygonal with distinct cell borders, a moderate amount of strongly amphophilic cytoplasm, and a round to oval medium-size nucleus. Cells with a mesenchymal phenotype are spindloid, with distinct cell borders, a small to moderate amount of acidophilic cytoplasm, and an elongated hyperchromatic nucleus. |