Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Left lung base opacity appears decreased in extent since prior imaging . Otherwise , imaging appears unchanged from prior exam . Well - circumscribed round mass projecting over the mid right lung is again seen , consistent with primary lung cancer . Right Port - A - Cath again seen terminating in the upper mid SVC .
    OUTPUT:
    
Improving left lung base opacity .