Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a new 7 cm rounded opacity projecting just to the left of the aortic arch which was not present on prior . Silhouette of the aortic arch and proximal descending aorta is preserved as is the left pulmonary artery . Linear left basilar consolidation is noted with new elevation of the left hemidiaphragm . There is also moderate hiatal hernia . The right lung is grossly clear . The cardiomediastinal silhouette is within normal limits .
    OUTPUT:
    
Rounded opacity projecting just lateral to the aortic arch . The etiology is uncertain , potentially underlying mass lesion although aneurysm could also be considered . Additional left basilar opacity likely in part with component of volume loss .