Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates interval placement of left - sided chest tube . There has been resolution of the previously seen small left - sided pneumothorax . There is mild widening of the superior mediastinum , which is unchanged from the prior exam . A linear lucency projecting over the cardiomediastinal silhouette raises concern for pneumomediastinum . There is no substantial pleural effusion or focal lung consolidation . Heart size is normal . There has been interval increase in the degree of massive subcutaneous emphysema extending into the supraclavicular soft tissues and into the neck .
    OUTPUT:
    
1 . Resolution of small left - sided pneumothorax . 2 . Interval increase in degree of extensive subcutaneous emphysema and probable pneumomediastinum .