13-year-old male neutered crossbreed. Previous history of cough and mild anorexia. X-rays revealed a possible mediastinal mass. A thoracic CT scan was performed.
There is moderate/marked dilatation of the right auricle (red arrows), that appears as a structure with a very thin wall, homogeneously filled with contrast, connected to the right atrium, and prolapsing towards the cranioventral mediastinum located ventral to the cranial vena cava (blue arrows). There is no filling defect or other abnormalities within the right auricle.
Moderate right auricle aneurysm, with mild prolapse towards the cranioventral mediastinum. The aetiology of this finding is uncertain, although it is described that this could be associated with a focal defect in the pericardium and concurrent herniation of the right auricle, or it could also be unrelated to a pericardial defect (secondary to inflammatory alterations, among others). The clinical significance of this finding is uncertain.
Cardiac evaluation, including ECG and echocardiography, is recommended to try to detect other alterations associated to the findings in the right auricle.
The following might be of interest:
- Aneurysmal dilatation of the right auricle in two dogs. Schwarz T. et al JAVMA, Vol 226, N9, 2005
- Imaging diagnosis-Intrapericaldial right auricle aneurysm in a dog. Toaldo et al. Vet rad US, Vol. 51, N5, 2010