Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient has already been investigated for an anterior mediastinal mass that is unchanged . There is no pneumothorax and pneumomediastinum after procedure . There is no pleural effusion . The lungs are otherwise clear .
    OUTPUT:
    
There is no significant change since prior exam in this patient with known anterior mediastinal mass . There is no pneumothorax or pneumomediastinum .