Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been interval removal of the left - sided chest drain . There is a persistent small left apical pneumothorax . A small amount of air seen in the mediastinum . Moderate subcutaneous emphysema is also noted . There is partial silhouetting of the left heart border which may be due to consolidation or atelectasis in the lingula . The cardiac shadow is enlarged consistent with the patient 's known pericardial effusion . The right lung appears clear .
    OUTPUT:
    
Small left apical pneumothorax . A small amount of air appears to be tracking along the mediastinum .