Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are bilateral pulmonary masses scattered throughout the lungs . There is no effusion or pneumothorax . Cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities identified . No free intraperitoneal air .
    OUTPUT:
    
Bilateral pulmonary masses most concerning for metastases in the setting of a known primary malignancy .