Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a large mass measuring approximately about 6 .5 cm in diameter within the right upper lobe but decreased substantially . Elsewhere , the lungs remain clear . The cardiac , mediastinal and hilar contours appear within normal limits . There is no pleural effusion or pneumothorax . Mild degenerative changes are similar along the thoracic spine .
    OUTPUT:
    
Persistent large mass in the right upper lobe , decreased in size . No evidence of superimposed acute disease .