Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: An upper mediastinal mass corresponds to a known thyroid goiter . The mediastinal and hilar contours appear unchanged . The heart is normal in size . There are no pleural effusions or pneumothorax . Opacities in the lower lungs clear with better inspiration on a second view , most consistent with dependent changes and atelectasis .
    OUTPUT:
    
No evidence of acute disease .