Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . There is persistent left perihilar opacity which is not significantly changed from the prior exam and may reflect known lung cancer or treatment related scarring . No definite signs of pneumonia . No pleural effusion or pneumothorax . Heart size is normal . Bony structures remain intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Similar overall appearance of left perihilar opacity , may reflect known primary lung cancer or treatment related fibrosis .