Cancer of the left lung with persistent left superior vena cava.

As operations for lung cancer become more common, more anomalies of various pulmonary arteries and veins are being encountered. Persistent left superior vena cava (PLSVC) is caused by abnormal development of the sinus venosus in early fetal life. In cases of PLSVC with left lung cancer, particular care must be exercised during the excision of the pulmonary vein, focusing on the region into which the PLSVC flows. In such anomalous cases, proper excision of the pulmonary artery and vein and lymph node dissection require a firm grasp of anatomic detail using preoperative computed tomographic scanning.