Hemorrhagic stroke in a dog with anaplastic carcinoma of the mammary gland

ABSTRACT

Background: Anaplastic carcinoma of the mammary gland is considered a highly invasive and malignant neoplasia, whichusually leads to neoplastic thrombosis and epidermal ulceration due to invasiveness of lymphatic vessels by tumor emboli.Loss of epidermal barrier predisposes to secondary bacterial infection, mainly by commensal bacteria of the skin, andsepticemia can be observed in cases of systemic dissemination. Neoplastic emboli and septic thrombi can lead to vascularobstruction, which can predispose to infarction in multiple organs. The aim of this case report is to describe a case ofhemorrhagic stroke in a dog with anaplastic carcinoma of the mammary gland.Case A 12-year-old, mixed breed, female spayed canine presented with mammary tumor with plaque formation, associatedwith skin ulceration which extended to the medial region of pelvic limbs. The animal also displayed neurologic clinicalsigns characterized by stupor, opisthotonos and apathy. Due to poor prognosis, the canine was euthanized and submittedto necropsy. During external examination, the animal was in a good body condition, had moderately pale mucosae, andit was noted a nodular plaque in the abdominal ventral area extending from thoracic to inguinal mammary gland. Themass was firm and white, extensively ulcerated, and extending from the thoracic to inguinal mammary gland. There wasa well circumscribed area of infarction in the spleen and kidney. In the cerebral cortex it was observed an extensive areaof hemorrhage with adhered blood clot from frontal to temporal lobe. There were multiple well circumscribed, firm, andwhite areas in the myocardium. Histologically, the neoplastic proliferation was composed by epithelial cells with high pleomorphism, features of malignancy, and no delimitations, leading to the diagnosis of anaplastic carcinoma of the mammarygland. Admixed with tumor cells there were multiple areas of hemorrhage, necrosis and thrombosis...