EXCISION OF A LOCALLY INVASIVE THYMOMA CAUSING CRANIAL VENA-CAVAL SYNDROME IN A DOG

A 9-year-old female Golden Retriever was examined because of inappetan ce, labored breathing, edema, and distention of the veins of the neck. Thoracic radiography revealed pleural effusion and a cranial mediasti nal mass. Biopsy results obtained by use of fine-needle aspiration wer e consistent with thymoma. At surgery, the tumor was found to have inv aded the cranial vena cava. Extra- and intravascular portions were rem oved without complications, and the dog's clinical signs resolved. To our knowledge, this is the first documented report of an invasive thym oma causing cranial vena caval syndrome that has been successfully tre ated in a dog. In this instance, the simplest surgical method, namely venotomy and tumor extraction using venous inflow occlusion, was succe ssful, obviating the need for temporary or permanent vascular conduits or grafts. These findings indicate that there is potential for surgic al correction of invasive thymoma with cranial vena caval syndrome in some animals, and the prognosis is not always poor.