A case of bilateral superior vena cava with variations in the azygos system and in the heart.

A case of bilateral superior vena cava is described in an adult cadaver of undetermined sex and age. The persistent left superior vena cava had a larger diameter approximately equal to that of the right superior vena cava ending in a wide caliber coronary sinus. Variations in the azygos system were also found. The ventricles show thin walls with trabeculae carneae forming one to five strata in the left ventricle, and from one to three strata in the right ventricle.