Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a ___ .4 x 8 .7 cm left perhilar mass . For the most part its borders are fairly well - defined and smooth . No additional mass lesions are seen . The lungs and pleural spaces are otherwise clear without evidence of pneumothorax or pleural effusions . The heart is normal in size . Mild degenerative change is seen throughout the thoracic spine with spurring . There is no evidence of pneumoperitoneum .
    OUTPUT:
    
Large left perihilar mass ; differential diagnosis includes malignancy but smooth borders may indicate a cystic or benign lesion . Chest CT , preferably with intravenous contrast , is recommended to characterize further . These findings were discussed with Dr . ___ by Dr . ___ at 3 : 16 p .m . on ___ via telephone .