Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a persistent opacity at the lateral aspect of the left lung since ___ . The lungs are otherwise clear . The cardiomediastinal silhouette is within normal limits . Atherosclerotic calcifications noted at the aortic arch . Folds lateral right clavicular fracture is again noted .
    OUTPUT:
    
Persistent left lateral lung opacity . While this may represent recurrent pneumonia , given presence since ___ the possibility of underlying mass lesion is not excluded . Followup is recommended 6 weeks post treatment to document resolution .