Isolated left thoracic isomerism with lung cancer: report of a case.

Thoracic isomerism, or symmetric morphology, is frequently associated with cardiac and abdominal anomalies. We report an unusual case of isolated left thoracic isomerism with lung cancer. A 67-year-old woman was referred to our hospital for investigation of an abnormal shadow on a chest X-ray. Chest computed tomography (CT) showed bilateral hyparterial bronchi, and bronchofiberscopy showed bifurcation of the right main bronchus into two branches. Pulmonary arteriography subsequently revealed that the right pulmonary artery bifurcated at the hilum and that it was not a mirror image of the left pulmonary artery. No other malformations were found on echocardiography or abdominal CT scan. We performed segmental resection of right S(1+2) and S(3) for lung cancer and the patient had an uneventful postoperative course. It is important to clarify the anatomy of patients with thoracic isomerism before surgical manipulation.