Anomalous intrathoracic left vagus and recurrent laryngeal nerve course.

An anomalous course of the vagus nerve is an extremely rare congenital anomaly. We report the case of a 59-year-old man who had left lung cancer. We performed a left upper lobectomy and mediastinal lymphadenectomy, paying attention to the pathway of the left vagus nerve, which had an anomalous course passing anteriorly to the left pulmonary trunk between the apical and anterior branches. The left recurrent laryngeal nerve hooked around the lower border of the apical branch of the left pulmonary artery.