Azygos Vein Aneurysm: A Rare Cause of Posterior Mediastinal Mass

Azygos vein aneurysm is a rare cause of mediastinal mass and is usually an incidental finding on chest radiography. Nowadays the diagnosis is made by non-invasive tests such as CT thorax and/or magnetic resonance imaging. Here we report a case of a female in whom a mediastinal mass due to an azygos vein aneurysm was diagnosed by CT chest, the aetiology of which, in all probability, was idiopathic.