Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP view of the chest demonstrates interval increase in opacification of the right lung , which likely represents combination of pleural fluid and patient 's known right lung mass . Small portion of the right lung remains aerated in the lower lung zone , with increased opacification , likely due to overlying fluid . The left lung is essentially clear . Ill - defined opacity in the left upper lung likely corresponds to FDG - avid nodule seen on ___ PET - CT exam . There is no left pleural effusion . No pneumothorax . Hilar and mediastinal silhouettes are unchanged . There is no mediastinal shift . Heart size is normal .
    OUTPUT:
    
In comparison to ___ exam , there is interval progression of the right lung opacification , which likely reflects combination of increased pleural fluid , patient 's known right lung mass and atelectasis . Superimposed infection can not be excluded in the appropriate clinical setting .