Biphasic pericardial and pleural mesothelioma in a cat: a case report

An 11-year-old castrated male Persian cat was admitted to the veterinary clinic showing signs of lethargy, lack of appetite, laboured breathing, dyspnoea, and cyanosis. The echocardiogram showed a large amount of pleural effusion, fibrin, and a mass measuring 1.89 cm in diameter adhered to the parietal pericardium. Upon necropsy, several nodules were observed on the pericardium sac and pleura. Histological evaluation of the nodules and mediastinal lymph node revealed the presence of neoplastic cells of epithelial and mesenchymal origin. Immunolabelling was positive for both cytokeratin AE1/AE3 and vimentin in the primary tumour and in the mediastinal lymph node. In the present report, immunohistochemical analysis supported the diagnosis that had been obtained based on clinical signs, histopathological examination, and echocardiogram.