Malignant aortic body tumor in a Korean Jindo dog

A 7-year-old, intact female Korean Jindo dog was referred due to ataxia and pain on palpation of the thorax. Radiograph, echocardiography and computed tomogram revealed a mass on the heart base region and osteolytic change of fifth thoracic (T5) vertebra. At necropsy, a firm, encapsulated and round mass was seen arising from the heart base region surrounding the ascending aorta and pulmonary artery. Histopathologically, nests of cuboidal and polyhedral cells having abundantly granular and eosinophilic cytoplasm with round to oval nucleus were separated by fibrous septa. Immunohistochemistry using chromogranin A revealed that tumor cells were originated from neuroendocrine organ and metastasized into some organs including lung, spleen, liver, kidney and T5 vertebra. By electron microscopy, we found the electron-dense and membrane-bound granules in cytoplasm of the tumor cells. This study provides the uncommon evidence that aortic body tumor metastasized to both multiple organs and bone.