Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: When compared to prior x-ray , there is apparent interval progression of the opacity in the left lung . Left upper and middle lung field opacity is more confluent . The right lung is grossly clear . Right - sided port catheter tip is seen in the upper right atrium . Cardiomediastinal silhouette is unchanged .
    OUTPUT:
    
Apparent interval progression of disease in left mid to upper lung compatible with underlying central mass lesion with superimposed postobstructive pneumonia and / or atelectasis .