Anomalous right upper lobe venous drainage.

Anomalous pulmonary venous return is a rare congenital anomaly mainly involving the right lung and is often associated with congenital intracardiac malformations as atrial septal defect. We report a case of anomalous right upper lobe venous drainage resulting in two right upper lobe veins draining into the azygous vein and into the confluence between superior vena cava and azygous vein, respectively. Preoperative identification of such an aberrant venous drainage is useful for avoiding unexpected intraoperative bleeding.