Kaoru Kaseda1, Taichiro Goto2, Katsura Emoto3, Yuichiro Hayashi3. 1. Division of General Thoracic Surgery, Dept of Surgery, School of Medicine, Keio University, Tokyo, Japan. 2. Division of General Thoracic Surgery, Dept of Surgery, School of Medicine, Keio University, Tokyo, Japan taichiro@1997.jukuin.keio.ac.jp. 3. Dept of Pathology, School of Medicine, Keio University, Tokyo, Japan.