Pitfalls in the plain film evaluation of the thoracic aorta: the mimicry of aneurysms and adjacent masses and the value of aortography. Part I. Transverse aortic arch.

In five instances, transverse aortic arch aneurysms were found that had initially, clinically and radiographically, mimicked thoracic neoplasms. Transverse aortic arch aneurysms display a wide spectrum of presentation: they may be asymptomatic, or they may cause symptoms secondary to esophageal, bronchial, vascular, or neural compression within the mediastinum and so mimic neoplasms. Conventional radiography in four projections and tomography are important components of the diagnostic evaluation of middle mediastinal masses. However, because plain film analysis is unable confidently to distinguish selected uncalcified aortic arch aneurysms from neoplasms, thoracic aortography is essential to the diagnosis.