Pancoast tumor on MRI

Sagittal T1-weighted section through the lung mass shows extension through the apical fat pad into the base of the neck (arrow). The mass partially surrounds a patent left subclavian artery (arrowhead) and obliterates the tissue plane containing the brachial plexus. The left brachiocephalic vein is occluded and cannot be seen. A corresponding section from the right side of the neck is included for comparison.