Primary renal hemangiosarcoma with brain and lung metastasis in a dog

Hemangiosarcoma (HSA) is a malignant tumor derived from the endothelium of vessels, and primary renal HSA is a rare variant of the disease. This study aimed to report a case of unilateral primary renal HSA with pulmonary and brain metastasis in a dog. A 10-year-old mixed-breed male dog was treated at the Hospital Professor Ricardo Alexandre Hippler from Universidade Vila Velha (HV-UVV) with signs of hematuria. A mass in the left kidney was detected by ultrasound, and no metastasis was detected on chest radiography. Unilateral nephrectomy was performed, and the material underwent histopathological examination, which was concluded as HSA. The animal died 48 days after surgery, and a necropsy was performed, showing marked hemothorax and multifocal metastasis of HSA in the lung and brain. The absence of nodules at other sites before surgery indicates a primary renal origin. The late diagnosis of the disease may have contributed to the spread of metastasis and, consequently, the development of hemothorax. Histopathological and necroscopic examinations were essential to confirm the diagnosis.