An 82-year-old male patient presented for elective computerized tomography (CT) guided biopsy of a mediastinal mass. He reported dyspnea on exertion for the past 2 months. He had a past medical history of coronary artery disease status post coronary artery bypass graft surgery (left internal mammary artery to left anterior descending [LAD] artery, saphenous vein graft [SVG] to first obtuse marginal, and SVG to posterior descending artery [PDA]) in 2010. He underwent cardiac catheterization 1 year ago for unstable angina that showed occluded vein graft to the PDA, and other grafts were widely patent. The native coronary artery was stented. The patient has a history of paroxysmal atrial fibrillation on anticoagulation and hypertension. He has been compliant with his medications. His vitals were stable, and his examination was unremarkable. His chest roentgenogram showed a mass in the right cardiophrenic angle. A CT of the chest with intravenous contrast to evaluate the mass showed a right side anterior mediastinal mass measuring 5.8 x 6.3 x 5.4 cm. The attenuation within the lesion was solid. There was no evidence of mediastinal lymphadenopathy.
The patient presented to the interventional suite for biopsy. The biopsy needle was inserted in the right chest wall and directed to the mass. Frank blood was aspirated. An aortogram was performed; see Images 1 and 2 that follow.
What is the patient's diagnosis?