Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to serial exams dating between ___ and ___ , a large conglomerate area by opacification in the left upper hemi thorax has worsened in demonstrates relatively round borders inferiorly . This is most likely predominantly intraparenchymal with adjacent potential loculated fluid component . Remainder of the lungs are grossly clear . Cardiomediastinal contours are stable . Small pleural effusions are again demonstrated bilaterally .
    OUTPUT:
    
Worsening large area of opacification in the left upper lung , which has waxed and waned on serial postoperative radiographs . Differential diagnosis includes postoperative infection , hemorrhage , aspiration , and an atypical manifestation of atelectasis . Consider chest CT for further evaluation .