1 Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, The Jikei University School of Medicine, Nishi-Shinbashi, Minato-ku, Tokyo, Japan.
2 Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, The Jikei University School of Medicine, Nishi-Shinbashi, Minato-ku, Tokyo, Japan. myanagaki@jikei.ac.jp.
3 Department of Pathology, The Jikei University School of Medicine, Nishi-Shinbashi, Minato-ku, Tokyo, Japan.