Invasive thymoma with venous intraluminal extension: CT and MRI findings.

We herein report an unusual case of invasive thymoma with venous intraluminal extension. The thymoma extended into the superior vena cava, the left brachiocephalic vein, and the proximal portion of the left jugular and subclavian veins intraluminally. It was suggested that the tumor had a discrete intravascular growth via the thymic vein into the left brachiocephalic vein and extended into the proximal portion of the left jugular and subclavian veins in the opposite direction of the venous stream.