Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperinflated . A stable , well - defined rounded opacity projecting over the left lower lung field was present in prior chest radiographs in approximately the same location and likely represents a nipple shadow . No other focal opacities are seen . Cardiomediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Unremarkable chest radiographic examination .