Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear . Cardiomediastinal and hilar contours are normal . No pleural effusions or pneumothorax . The mid-sternum ( upper body ) is bowed posteriorly , but there is no cortical break . The presternal soft tissue may be swollen . There is no retrosternal pleural or anterior mediastinal abnormality . The region can be readily evaluated by palpation to see if this is a normal anatomic variant or the result of trauma . No displaced rib fractures are identified .
    OUTPUT:
    
Sternal abnormality could be normal anatomic variant or result of trauma , recent or remote . Clinical examination can differentiate . Please note that radiography is not sensitive for chest wall trauma .