Axial computed tomography with contrast image of the chest. Contrast within the vessels appears white. A heterogeneously enhancing mass is seen occupying the anterior mediastinum (asterisk). There is significant compression of the trachea (black arrow) at the level of the carina, which is smaller in diameter than the adjacent orogastric tube (black circle). White arrows indicate brachiocephalic, left carotid, and left subclavian vessels just superior to their origins from the aortic arch. The superior vena cava (which should be in the vicinity of the white circle) is conspicuously absent.