Occasionally, a goiter may grow into the mediastinum and displace the trachea and esophagus, thus causing difficulty in breathing and swallowing. This is easily demonstrated on a chest x-ray (left). The CT scan on the right shows an enlarged left thyroid lobe displacing and narrowing the trachea behind the sternal notch.
AP Chest x-ray of the patient depicted on the left showing tracheal compression
Axial CT scan of the patient on the left,showing the upper portion of a large right substernal goiter compressing and displacing the larynx to the left.
Coronal CT scan of same patient showing the large right substernal goiter compressing and displacing the larynx and the trachea to the left