Persistent left superior vena cava with bilateral azygos system in an adult.

The condition to be described was discovered during routine dissecting-room work in a man aged 88, who had no history of any illness during life, and whose death was due to bronchopneumonia. The left subclavian and internal jugular veins united in the neck to form a left superior vena cava which passed directly down over the arch of the aorta and the pulmonary trunk to lie between the left auricle anteriorly and the pulmonary vessels and bronchus in the root of the left lung posteriorly (Fig. 1). The vessel then turned to the right in the posterior part of the coronary sulcus and became continuous with the coronary sinus: its total length from origin to termination was 15 cm. On the arch of the aorta, the left vena cava received the left internal mammary and superior intercostal veins, and just before its termination it was joined by the left marginal vein from the anterior part of the