Portal de Pesquisa da BVS Veterinária

Acta sci. vet. (Impr.); 41(supl.1): Pub. 36, 2013. ilus

Artigo em Português | VETINDEX | ID: biblio-1372631

Resumo

Background: The most common abnormality associated to hyperthyroidism in cats is functional adenomatous hyperplasia. It might be present anywhere from the base of the tongue caudally to within the thoracic cavity, or even intrapericardial. Scintigraphic and computed tomography are useful imaging modalities to determine the location of hyperfunctioning thyroidal tissue. In cats, chylothorax can occur with several underlying disease processes, including congestive heart failure, mediastinal mass, heartworm infection and trauma, however it is commonly idiopathic. The aim of this study was to report the first case of chylothorax caused by intramediastinal ectopic thyroid adenoma in a cat. Case: A 19-year-old spayed domestic shorthair female cat was presented with difficulty breathing, dyspnea and hiporexia. The animal had history of chronic kidney disease, recurrent urinary tract infections and infl ammatory bowel disease, and had been receiving prednisolone and ceftiofur. Lung auscultation revealed silence on both Hemithorax and cardiac auscultation revealed reduced noise. Thoracic radiographs were performed, which revealed severe pleural effusion. Bilateral thoracocentesis was performed to avoid respiratory failure, and the fluid obtained was sent for cytological and biochemical examinations, which revealed the presence of chylothorax. Laboratory investigation including blood count and full biochemical screen were within normal limits, except for little elevated blood urea nitrogen and serum creatinine. Radiographs, ultrasonography and echocardiogram of thorax were performed post-drainage, and they did not reveal any abnormalities, leading to suspect of idiopathic chylothorax. In addition, computed tomography was performed to rule out all possibilities not identified in the other exams, which showed a mass at the cranial mediastinum. A cytological exam of the mass suggested thyroid adenoma. Therefore, the presumed diagnosis was chylothorax caused by compression of thyroid neoplasm. Then, three days later, the cat underwent sternal thoracotomy. The mass was on left of the midline, displacing esophagus and trachea. It was resected and a chest drain was placed. Within 24 h postoperatively, a little chylous effusion was drained, so the surgery was considered succesfull. However, the cat had low systolic blood pressure and rectal temperature, even with infusion of crystalloid and colloid and thermal mattress on. Hematological and biochemical exams were performed, which suggested sepsis. The animal died 30 h after surgical procedure. Histological examination of the resected mass was consistent with thyroid adenoma, and then it could confirm the cytological suggestion. Discussion: In cats, intramediastinal thyroid adenoma has been reported often being the result of one thyroid lobe descending into the thoracic cavity. Management of chylothorax should be directed at identification of the cause and treatment of the underlying disorder. However, often, it's cause is unknown due to the lack of access to advanced diagnostic techniques.Therefore it is necessary more accurate imaging modality, such as computed tomography and scintigraphy to define actual cause. This current case report is the first one that revealed chylous pleural effusions associated with ectopic thyroid. It was based on anatomic, clinical, surgical, laboratorial, tomographic findings, and in absence of significant formation of fluid postoperative.

Biblioteca responsável: BR68.1