PARTIAL AGENESIS OF THE AZYGOS VEIN - A CASE-REPORT

In the cadaver of an 86 year old man the inferior segment of the azygo s vein could not be found. Furthermore, a normally developed hemiazygo s vein drained the right and left intercostal veins from T 10 to T 6. This vessel finally curved towards the right to reach the superior ven a cava after having drained the right superior intercostal veins. The left superior intercostal vein ended in a short vessel draining into t he left brachiocephalic vein. This condition may be represented in a s tandard chest radiograph by the so-called ''aortic nipple''. Agenesis of the azygos vein, suspected because of the presence of this radiolog ical sign, should be confirmed in the living by means of computerized tomography. This can clarify the anatomy of the mediastinal vessels pr ecisely. Embryological pattern of the azygos system accounting for its possible defects is discussed.