Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate an approximately 6 x 5 cm opacity which obscures the right cardiac border on frontal view and overlaps with the heart on lateral view . The heart size is normal . The lungs are well aerated and are clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
6 x 5 cm opacity which is either in the anterior mediastinum or anterior right middle lobe . The differential diagnosis includes a fat pad , cardiogenic / pericardial cyst , lymph node , or thymic abnormality . CT chest , preferably with contrast , is recommended for further evaluation . These findings were discussed via telephone by ___ , MD , with ___ ___ , NP , at ___ on ___ , immediately upon discovery .