Hemangiossarcoma na língua de um gato / Hemangiosarcoma in a cat’s tongue

ABSTRACT

Background: Hemangiosarcoma is a primary malignant neoplasm of vascular endothelial cells, common in dogs and uncommon in cats. It is characterized by being aggressive and presenting high metastatic behavior. It corresponds to 0.5% to 2% of all feline neoplasms, with more reports in shorthaired cats aged between 8 and 12.2 years old, with no predisposition for sex or breed. Among the diagnostic methods, histopathological and immunohistochemical exams stand out because they are more accurate, since the result of fine-needle aspiration biopsy is usually hidden by blood contamination. This report aims to describe a case of a hemangiosarcoma in a cat’s tongue. Case A 9-year-old, female, shorthair cat with a history of weight loss, lethargy, chewing difficulty with the evolution of three months and two-day oral bleeding was attended. Physical examination revealed blood in the oral cavity, enlargement, and darkening of the tongue surface, normalized oral and ocular mucous membranes, estimated dehydration of 7%, a rectal temperature of 38.8OC, and pulmonary and cardiac auscultation without changes. The cat was hospitalized, and euthanasia was elected. Cytological and histopathological exams of the tongue were requested, which revealed a neoplastic proliferation of endothelial cells expanding and replacing the muscular layer of the tongue, forming primitive vascular structures filled with a large number of red blood cells and supported by a delicate fibrovascular stroma. There were moderate anisocytosis and anisocariosis and rare figures of mitosis. Immunohistochemical examination showed the expression of von Willebrand factor, smooth muscle vimentin, and actin in the cytoplasm of neoplastic cells, and negative staining for pancitokeratin. Discussion: According to the results of cytological, histopathological and immunohistochemical