Cytological aspects of equine oral fibrosarcoma

ABSTRACT

Background: Although mesenchymal neoplasms are prominent in horses due to the occurrence of sarcoids, other neoplasmsmay occur. Fibrosarcoma in horses is uncommon, notwithstanding, few studies have performed diagnostic techniques. Itis presumed, therefore, that other diagnostic methodologies should be explored. In this sense, fine needle aspiration cytology (FNAC) emerges as an effective, low-cost, and minimally invasive method to identify tumors in these animals. Theobjective of this study was to describe the use of FNAC in the diagnosis of oral fibrosarcoma in horses. Once fibrosarcomais an aggressive tumor, it is important to validate effective techniques for an early diagnosis.Case A 10-year-old male Quarter Horse was treated, with a clinical complaint of increased volume in the right maxillaryregion. This tumor occupied about » of the hard palate area. Hyporexia, hypodipsia, mild dehydration, and weight losswere observed at clinical examination. Complementary examinations were requested, and an extensive radiolucent masswith an indication of bone involvement was observed on the radiograph. The hemogram revealed normocytic normochromicanemia, in addition to lymphopenia. In the serum biochemistry test, AST (aspartate aminotransferase) and creatinine wereslightly increased. FNAC showed a malignant mesenchymal neoplasm, possibly fibrosarcoma. Due to its clinical worsening and lack of response to supportive treatment, humanitarian euthanasia was performed. Finally, a histopathologicalexamination confirmed the oral fibrosarcoma suggested by FNAC.Discussion: The early diagnosis of neoplasms is important for its correct treatment, as well as the prognosis. In this way,the combined use of complementary tests helps in the resolution of the case. FNAC is still little used in the examinationroutine in horses. In the present report, this test demonstrated efficacy since it revealed mesenchymal cells compatible withfibroblasts...