Hemangiossarcoma cutâneo com metástase no sistema nervoso central de um canino / Cutaneous hemangiosarcoma with metastasis in the central nervous system of a canine

ABSTRACT

Background: Canine hemangiosarcoma is a malignant neoplasm of endothelial cells. Such tumor has most commonly its primary location in the spleen, right atrium, subcutaneous tissue and liver. In general, metastases occur in the liver, omentum, mesentery and lung. The nervous system may be a metastasis site, but with rare spinal cord involvement. This paper aims at the description of canine cutaneous hemangiosarcoma with metastasis to the central nervous system. Case A dog presented history of skin neoplasia. The patient underwent physical examination, which detected an exophytic tumor in the foreskin. Needle aspiration of the lesion was carried out, suggesting the presence of malignant neoplasm of mesenchymal origin. So, the lesion surgical excision was the option. Before the procedure, complementary preoperative examinations of the patient were required. Those corresponded to chest radiographs, abdominal ultrasound, complete blood count, serum urea, creatinine, alanine aminotransferase, aspartate aminotransferase and total protein. The image diagnostic of the thoracic and abdominal cavities showed no noteworthy changes. The hematology and serum biochemistry were normal. The tumor obtained during surgery was sent for histopathological analysis, whose diagnosis corresponded to hemangiosarcoma. Chemotherapy treatment was not possible in the animal. Nine months after the surgery, alterations in the canine movement were detected as well as postural reactions of the right forelimb, with paresis and reduced proprioception of the same. Hyperesthesia was also found in the spine, in the cervical and thoracic segments. Due to the patient's clinical condition, euthanasia was recommended. The animal was sent for autopsy, where the main macroscopic lesions were dark red areas in the left brain and spinal cord compression by a tumor between the bodies of the seventh cervical vertebra and the first chest one. All material was sent for histopathological examination, which revealed the presence of hemangiosarcoma in the structures examined, suggesting metastasis to the central nervous system from the primary cutaneous site. Discussion: The majority of dogs with cutaneous hemangiosarcoma, during the initial clinical presentation, have already presented a primary tumor in another organ. However, in the present report, there was an inversion of this quotation, since the initial site of the tumor probably corresponded to the skin as, during the first approach, the patient's chest radiographs and abdominal ultrasound did not reveal metastastic injuries. Also, at that time, the dog did not exhibit clinical signs related to tumor spread, unlike the symptoms observed after nine months. To hemangiosarcomas with location in the frontal lobe of the brain, contralateral postural reaction deficits can be observed. Such statement may justify, for the case under discussion, the association of the lesions in the left cerebral hemisphere with disabilities in the proprioception in the right forelimb. Hemangiosarcomas of the spine with extradural location cause gradual compression of the spinal cord and thus favor the development of progressive myelopathy symptoms. This quote could explain the spine hyperesthesia and the monoparesis reported in the animal. The histopathology of skin tumors is essential to establish the definitive diagnosis and for better understanding of future pathologies.