Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . Mildly prominent upper mediastinal contours appear stable , however , since prior examinations . There is a nodular density projecting over the left lower lung of approximately 10 mm in diameter , suspected to represent a nipple shadow , but a pulmonary nodule can not be excluded . Otherwise the lung fields appear clear . There is no pleural effusion or pneumothorax . Mild degenerative changes are similar along the thoracic spine .
    OUTPUT:
    
1 . Nodular opacity projecting over the left lower lung , suggesting a nipple shadow , although a pulmonary nodule can not be excluded . Evaluation with a PA view with nipple markers is recommended with clinically appropriate . 2 . No evidence of acute disease .