Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well inflated and clear . Hyperinflation may be slight . A sharply marginated 13 mm opacity projecting over the left lower lung has no correlate on the lateral projection . No focal consolidation , effusion , or pneumothorax is present . Biapical thickening is mild . The cardiac and mediastinal contours are normal .
    OUTPUT:
    
Opacity projecting over the left lower lung is most likely a nipple shadow . A repeat chest radiograph with nipple markers is recommended for confirmation . Finding and recommendation was entered into the critical results reporting tool at ___ on ___ .