Thoracoscopic segmentectomy for lung tumour with displaced B^1 + 2

The frequency of bronchial branching abnormalities is about 0.6%, of which about 75% are related to the right upper lobe. The frequency of left B^1 + 2 transition bronchus is even rarer, but a few cases have been reported. A 43-year-old man, who presented with an abnormal pulmonary nodule suspected to be lung cancer in the left S4 segment, underwent video-assisted thoracoscopic segmentectomy of S3 plus lingular segment. Preoperative three-dimensional contrast-enhanced computed tomography (CT) revealed a displaced B^1 + 2 bronchus arising from the left main bronchus, which ascends behind the main pulmonary artery. Video-assisted thoracic surgery was performed successfully, and the nodule was pathologically diagnosed as a lymphoma. Preoperative three-dimensional contrast-enhanced CT was very useful to detect this rare bronchial abnormality. In the present case, three-dimensional CT allowed us to safely operate on a patient with a rare B^1 + 2 displaced bronchus in the left upper lobe.