Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The mediastinal and hilar contours are within normal limits . Again seen is a moderate - to - large left pleural effusion , stable to slightly increased in size since the last study . , with associated opacification of the left lung base . This may represent atelectasis or infection . A small right pleural effusion is likely present . Cardiac size can not be assessed due to the left pleural effusion .
    OUTPUT:
    
Stable to slightly enlarged left pleural effusion , now moderate - to - large . Small right pleural effusion .