Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are low in volume and show a nodular left lower lobe opacity , unchanged , most consistent with a nipple . The cardiac silhouette is top normal . The mediastinal silhouette is widened on both the frontal and lateral films with loss of the retrosternal clear space . The hilar contours and pleural surfaces are normal . No pleural effusion or pneumothorax is present .
    OUTPUT:
    
Mild progressive mediastinal widening could be related to an aortic aneurysm . Further evaluation with a cardiac echocardiogram or a chest CT maybe obtained .