Mediastinal thymoma invading the superior vena cava and the right atrium.

An 86-year-old male patient presented with a large mediastinal tumor. A needle biopsy was performed and revealed a diagnosis of invasive thymoma. Multidetector computed tomography (MDCT) angiography was performed in order to assess operability of the tumor. This showed a heterogeneously enhancing anterior mediastinal mass. The tumor had invaded the left brachiocephalic vein, presumably via the inferior thymic veins, which is a known feature of these tumors. The thymoma grew then endovenously through the superior vena cava into the right atrium. A pacemaker lead was completely encased by tumor tissue. The patient was deemed inoperable and underwent radiation therapy.