Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided Port - A - Cath is in unchanged and appropriate position . The heart is normal in size . Enlargement of the right hilum is re - demonstrated consistent with the patient 's known hilar mass . Linear opacity extending from the hilum into the right middle lobe with unchanged . Elevation of the right hemidiaphragm is noted and increased from the prior examination . New from the prior examination is increased opacity along the medial base of the right lung . No pneumothorax . Biapical scarring is stable . Pulmonary nodules are better appreciated on prior chest CT .
    OUTPUT:
    
Increased opacity at the medial right base which could be due to atelectasis given centrally obstructing lesion . Superimposed infection is difficult to exclude .