Citologia aspirativa por agulha fina como método diagnóstico precoce em enfermidades em medicina veterinária

Abstract

Fine-needle aspiration cytology is an easy, rapid, low cost, and minimally invasive technique, consequently contributes to a faster diagnosis leading to a faster decision, mainly to provide welfare and quality of life to patients. The objective of this study was to use FNAC in specific diseases of domestic animals. One study evaluated the association between cytopathology and histopathology diagnosis of mammary tumors in female dogs and described important cytology elements to further differentiate and classify tumors; and another study described cytological findings on bovine seneciosis. The first study included 101 samples of 61 dogs from 2012 to 2014. Cytologic examination classified 96 samples as malignant tumors and five as benign. Among all malignant tumors, the most frequent was simple carcinoma (54.17%), complex carcinoma (20.83%) and malignant mixed tumor (17.71%). Carcinosarcoma (4.17%), osteosarcoma (2,08%) and squamous cell carcinoma (1,04%) were the least common. Benign tumors were complex adenomas (n=2; 40%) and mixed tumors (n=3; 60%). Cytology diagnoses were compared to histopathology with 99% accuracy, 100% sensibility and 83% specificity. Cyto-histologic correlation was 92.50% for simple carcinomas, 57.89% for complex carcinomas, 57.14% for malignant mixed tumor, 27.27% for carcinosarcomas and 100% for osteosarcomas. Myoepithelial cells in nests were seen in both complex and mixed tumors and therefore should not be considered as a cytologic feature for differential diagnosis. Mesenchymal cells (probably fibroblasts) were differentiated from myoepithelial cells by FNAC, allowing us to differentiate simple carcinomas with desmoplastic reactions from complex and mixed tumors. Magenta matrix, interpreted as condroid/osteoid, was found in malignant mixed tumors (66.66%), carcinosarcomas (63.64%), benign mixed tumors (50%), osteosarcomas (50%), and complex carcinomas (10.53%). Abundant extracellular pink and finely granular matrix throughout the background was found in six malignant mixed tumors (28.57%), three carcinosarcomas (27.27%) and two benign mixed tumors (50%). This matrix was absent in complex tumors. For this reason, it can be used as an indicator of mixed tumors. The second study was performed on a bovine liver presenting clinical signs and history of Senecio spp. poisoning. Cytology slides showed megalocytosis, the main finding on histopathology to confirm the diagnosis. FNAC is not described as a diagnostic method for Seneciosis. Cyto-histo correlation was good, suggesting that FNAC can be used as a diagnostic method for bovine Seneciosis. Consequently, our results suggest FNAC as a valid method for diagnosing malignant mammary tumors in female dogs and also have efficacy on bovine seneciosis diagnosis. These results give an early and rapid diagnosis, allowing the veterinarian to choose the best treatment option, or determine the prognosis for an animal.