[A case report of anomalous left brachiocephalic vein].

An anomalous case of a left brachiocephalic vein passing behind the ascending aorta was observed in a 49-year Japanese man. This is known as anomalous left brachiocephalic vein. The anomalous left brachiocephalic vein descended along the left mediastinum in a position identical to that of a persistent left superior vena cava, so the diagnosis of this venous abnormally require carefully considered. Many cases of anomalous left brachiocephalic vein have been reported based on autopsy findings, but this venous anomaly was recently demonstrated by ultrasonography, CT, and MRI.