The case was 13-year-old man. He visited local hospital due to high fever and back pain. He was diagnosed as acute pleuritis based on a chest computed tomography( CT) scan and referred to our hospital for treatment. Chest CT scan revealed a round shaped mass with clear margin at the left vertebrophrenic angle. A neurogenic posterior mediastinal tumor was suspected. Thoracoscopic surgery revealed that the mass had 2 thin string-like structures connecting to the descending aorta, and was suspected to be a pulmonary sequestration. The resected tumor was pathologically confirmed to be an extralobar pulmonary sequestration most of which was hemorrhagic necrosis caused by arterial infarction.