Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs were obtained . The lungs are fully expanded and clear . There are persistent linear lucencies projecting over the neck , mediastinum , and along the cardiac border compatible with pneumomediastinum . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Persistent pneumomediastinum with extension to soft tissues of the neck , unchanged from prior study .