Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Large left superior mediastinal mass displacing trachea to the right with associated mild coronal tracheal narrowing is consistent with known longstanding left thyroid mass . The heart is upper limits of normal in size and demonstrates left ventricular configuration . Aorta is tortuous , without change . Coarse linear opacities are present at the left lung base as well as minimal linear opacities in the right lower lobe . No confluent areas of consolidation or pleural effusion are evident .
    OUTPUT:
    
1 . Large left superior mediastinal mass , consistent with previously described thyroid goiter on CT cervical spine study of ___ . 2 . Bibasilar linear atelectasis and / or scarring .