Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable view of the chest . No prior . Linear lucency along the left side of the mediastinum and within the mediastinum superiorly is compatible with pneumomediastinum . Extensive subcutaneous gas extends into the neck and right greater than left chest wall . There is no definite pneumothorax identified on either side , noting that trace apical pneumothorax could be obscured by overlying subcutaneous emphysema . The lungs are clear of focal consolidation .
    OUTPUT:
    
Pneumomediastinum and extensive subcutaneous gas . No visualized pneumothorax .