Ductular mammary carcinoma in a lioness

Well bordered solid enlarged 16.7x9.7x8 cm in the size neoplasma was found in a 7-year-old lioness without any clinical signs of diseases in Chonju city zoo and surgically removed. Simple lobes were separated by pale gray yellowish fibrous tissue. The tumor parenchyma was yellowish with numerous cysts, necrotic foci and hemorrhages. Histologically neoplasma was composed of cell nests different in the size and shape with high mitotic activity. Slow invasive spreading on the border was observed. Formation of the narrow ductular lumina bordered the flattened cells leading to keratinization was seen in some places. It was noted by supplemental clinical investigations, that the tumor did not metastasized to other organs. This tumor is considered to be a sample of a malignant tumor without metastatic spreading and was note described in literature yet.