Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A rounded mediastinal mass is present in the region of the thoracoabdominal junction measuring about 6 .6 cm in diameter and apparently containing peripheral calcifications on the lateral view . It is difficult to separate from the descending thoracic aortic interface on the PA view , suggestive of a calcified aortic aneurysm . A mass arising in the lower esophagus is less likely . Heart size and pulmonary vascularity are normal . Lungs are clear except for linear atelectasis in the left lower lobe .
    OUTPUT:
    
6 .6 cm diameter lower mediastinal mass with apparent peripheral rim of calcification . This is incompletely characterized but is concerning for a localized aneurysm of the thoracoabdominal aorta . A mass arising from the lower esophagus is less likely . CT is recommended for further evaluation as communicated to Dr . ___ on ___ at 7 :45 a .m . at the time of discovery .