Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Extensive subcutaneous gas projects over the chest wall and imaged portion of the lower neck . Lucency at the mediastinum is also compatible with pneumomediastinum . No definite pneumothorax identified given limitation of overlying gas within the overlying soft tissues . No acute osseous abnormalities identified .
    OUTPUT:
    
Extensive subcutaneous gas and pneumomediastinum .