Congenital absence of the azygos vein with persistent left superior vena cava: A case report

Absence of the azygos vein is a very rare variant of venous tributary arrangement which has been reported only in few cases so far. We hereby introduce the chest radiographic and computed tomographic findings of the congenital absence of the azygos vein with bilateral superior vena cava, incidentally detected during a follow-up for rectal cancer. The hemiazygos vein is drained into persistent left superior vena cava via left superior intercostal vein, so called the 'aortic nipple'.