Osteossarcoma mamário com êmbolo neoplásico em cerebelo / Mammary osteosarcoma with neoplastic emboli in cerebellum

ABSTRACT

Background: The mammary neoplasms are highly frequent in female dogs. It is characterized by the proliferation of epithelial or mesenchymal cells. The mammary osteosarcoma is a example of the proliferation of the last group and its main feature is production of osteoid matrix and areas of mature bone tissue formation. Metastases to the lungs and regional lymph nodes are frequent, however some other metastasis sites have been reported. The aim of this study is to report a mammary osteosarcoma in a 12-year-old mixed-breed female dog with multiple metastases and neoplastic emboli to the central nervous system. Case The animal was brought to the Veterinary Hospital of the Uberlândia Federal University (HV/UFU) with the complaint of increase in the volume of the mammary glands. The cytopathological exams was performed in the mass that measured 15 cm of diameter and covering a large region of the mammary gland, from the right cranial thoracic to the right cranial abdominal mammary gland. The cytological diagnostic was inconclusive because of the lack of material for diagnosis. Therefore, total unilateral mastectomy was performed for histopathology analysis. The material was then sent to the Animal Pathology Laboratory of the HV/UFU where routine processing was performed. The microscopy showed proliferation of mesenchymal cells arranged in bundles with intense pleomorfism and producing osteoid matrix, leading to the diagnosis of mammary osteosarcoma. Around 15 days after the diagnostic the animal died and was sent the Animal Pathology Laboratory of the HV/UFU for necropsy. During the external exam there was a mass at the same site of the primary mass previously extracted. Besides it, there were masses affecting lungs, intestine and kidneys. The histopathological exam showed sites of metastasis of osteosarcoma in the organs described, as well as neoplastic...