Azygos Vein Aneurysm Mimicking a Mediastinal Mass

Abstract

Azygos vein aneurysm (AVA) is a rare thoracic pathological entity that mimics a posterior mediastinal mass as well as a right paratracheal mass. Usually asymptomatic, AVA is often accidentally discovered during routine chest x-rays; however, depending on the aneurysm size and complications, some symptoms may be present. The aim of this paper is to report a case of idiopathic AVA and to discuss its aetiology, embryonic origin, symptoms, complications, diagnostic methods and treatments. A 74-year-old female was investigated for diffuse thoracic pain and submitted to standard chest x-ray, which identified a right paratracheal, well-defined, homogenous opacity, considered to be part of the mediastinal shadow. The patient was further submitted to thoracic computed tomography, which confirmed the presence of a tumoral mass at the level of the right paratracheal area. The patient was submitted to surgery and the tumoral mass was resected; however, the tumor proved to be a completely thrombosed aneurism of the azygos vein arch. AVA is a rare pathology that must be taken into consideration during the differential diagnosis of right postero-superior mediastinal masses.