Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to ___ , the lungs remain mildly hyperinflated with a background of emphysema . Again seen is a left hilar mass . There is mild left lower lung atelectasis . No definite pleural effusion . No pneumothorax . Heart size is normal and unchanged . The aorta is tortuous . The aorta is calcified , indicating atherosclerosis . There are multilevel degenerative changes of the visualized spine .
    OUTPUT:
    
Left hilar opacity consistent with known malignancy . No convincing signs of superimposed pneumonia . Background emphysema again noted .