Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are normal . The lungs demonstrate subtle wispy opacity in the left upper lobe , not present on prior exam . Flattened hemidiaphragms suggest chronic obstructive disease . There is no pleural effusion or pneumothorax . Bilateral glenohumeral joint degenerative changes are noted .
    OUTPUT:
    
Subtle wispy opacity in the left upper lobe may represent early pneumonia ; recommend follow - up to resolution to exclude underlying mass .