Anomalous right upper lobe pulmonary veins draining posterior to the pulmonary artery.

The anatomy of pulmonary vessels varies. The right upper pulmonary vein usually drains in front of the pulmonary artery to the left atrium. We herein describe a case of the right upper lobe pulmonary vein draining posterior to the pulmonary artery and absent right upper lobe pulmonary vein in the ventral hilum. A 64-year-old woman suspected to have lung cancer and scheduled for surgery underwent pre-operative three-dimensional computed tomography (3D-CT), which revealed that pulmonary vessels V1 + 3 and V2 drain posteriorly to the pulmonary artery. Video-assisted right upper lobectomy was performed because the patient was diagnosed with lung adenocarcinoma through intraoperative pathologic analysis, and all the pulmonary vessels were identified correctly during the operation. Despite the limited surgical field of video-assisted lobectomy, the operation was performed safely because the pre-operative 3D-CT assessment revealed the anatomy of the anomalous pulmonary vessels, helping us avoid missing any anomaly and vessel injury.