Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Comparison is made with the next preceding portable chest examination of ___ . Heart size and thoracic aorta appear unchanged . Pulmonary vasculature not congested . There is a large density in retrocardiac position in the left lower hemithorax with atypical air - fluid level . This appears to be a pulmonary cavitation which probably has been drained on earlier occasion . time . In comparison with the next preceding portable chest examination of ___ , this cavity with air - fluid level has developed in the area of a previous atelectasis . A chest CT of ___ is reviewed , reveals necrotic left lower lobe mass . This explains the finding on the present chest examination .
    OUTPUT:
    
Air - fluid level in necrotic left lower lobe mass related to lung cancer . Presently no cardiac enlargement or pulmonary congestion and no evidence of secondary pulmonary deposits .