What are the findings and diagnosic possibilities?

Rounded shadow in the left upper zone is due to an aortic arch aneurysm. Another possiblity is an aneurysm of the ductus, which can also rarely occur after surgical closure of patent ductus arteriosus. Lymph nodes in the region as in lymphoma can also produce a similar appearance. An aneurysm in this location can produce hoarseness of voice by left vocal cord palsy as a result of compression of the left recurrent laryngeal nerve.

CT scan of aortic arch aneurysm

CT scan of thorax showing aortic arch aneurysm. The single tracheal air column identifies the level above the tracheal bifurcation (below the bifurcation, two air columns of the right and left bronchi would be seen). The negative shadow outside the contrast filled region is likely to be an adherent thrombus within the aneurysm.