Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Normal cardiomediastinal and hilar contours . Normal pleural surfaces . A subcentimeter opacity at the left base is again seen and likely represents a nipple shadow . Increased , ill - defined opacity at the right base could represent superimposition of normal bronchovascular structures , but early pneumonia can not be excluded .
    OUTPUT:
    
Increased , ill - defined opacity at the right base could represent superimposition of normal bronchovascular structures , but early pneumonia can not be excluded .