A Rare case of Azygos vein arch Aneurysm: A case report

Background: The aneurysm of the azygos vein (AVA) is a dilatation of the azygos vein (AV) over 1,5cm; it is very rare, mostly fusiform and affecting people between 19 and 70 years old. Aetiology can be traumatic, inflammatory/infectious, cardiogenic, neoplastic or idiopathic. The weak points for the development of an AVA are essentially two: the confluence of the AV in the superior vena cava (SVC) and the convergence among its embryologic constituents. AVA is often asymptomatic, therefore it can be an incidentaloma. Symptoms, usually due to compression of neighbouring structures (such as trachea, bronchi, SVC, inferior vena cava (IVC), oesophagus or nerves), can simulate a mediastinal mass. The main complication of AVA is thrombosis, which can extend to pulmonary vessels. Other complications include rupture, fistulae and dissection. Most of the authors consider the occurrence of complications the only indications to treat it. Case report: We present the case of an 87-year-old woman with chronic atrial fibrillation, which came to our emergency department for wheezing and dyspnoea. Though the chest radiograph only found a pleural effusion, the subsequent CT scan showed a voluminous mediastinal mass compressing the oesophagus, which proved to be an AVA during the dynamic phase of the study. Conclusion: The AVA represents a possible hypothesis in the differential diagnosis of mediastinal masses, that in most cases can be probed radiologically.