A Case of an Aortic Lipoma in a Dog

Introduction: A 6-year-old German shepherd dog was referred for investigation of lethargy, weakness and dyspnoea. Computed tomography revealed the presence of pleural and pericardial effusions and masses within the lungs and near the heart base. Materials and Methods: The dog was humanely destroyed and a routine post-mortem examination was carried out. The mass near the heart base was observed to be within the wall of the aorta at the aortic arch. Multiple sections of this mass and the masses within the lungs were fixed in 10% neutral buffered formalin and processed routinely. Sections were stained by haematoxylin and eosin. Results: Histopathological examination of the mass revealed it to be composed of sheets of well-differentiated adipocytes, and the mass appeared to arise within the adventitia of the aorta. The mass was therefore diagnosed as a lipoma. The pulmonary masses were diagnosed as bronchoalveolar carcinoma, thought to be unrelated to the lipoma. Conclusions: Two cases of aortic lipomas have been reported in man, but this is the first report of this lesion in veterinary medicine.