Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to a chest radiograph obtained approximately 5 days prior , no significant changes are appreciated . The lungs are fully expanded and clear without focal consolidation . Costophrenic angles not well visualized , but likely due to soft tissue attenuation rather than pleural effusions , which would be tiny if present . Heart size is normal . Large , retrocardiac soft tissue abnormality mentioned on preoperative chest radiograph remains present .
    OUTPUT:
    
No acute cardiopulmonary abnormalities . Previously identified , large , retrocardiac soft tissue abnormality is most likely a hiatal hernia , but also on the differential are a large , lower esophageal mass or descending thoracic aorta aneurysm . Recommend correlation with prior imaging if available .