A unique presentation of anomalous posterior intercostal veins, hemiazygos vein and left superior vena cava

Abstract

The venous anomalies of thorax are common, but the only drainage of 1st and 2nd posterior intercostal veins on both sides into the internal vertebral venous plexus with no communication to the azygos system is reported for the first time. The common hemiazygos vein is singular receiving all the posterior intercostal veins on the left from 4th to the 11th with subcostal on the left side. This vein drains into azygos on the right. It also connects on the cranial end via an anomalous vein to the Left SVC. This anomalous vein also receives the left 3rd posterior intercostal vein. On the right, the azygos system is normal.