1 Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-Chzo, Chuo-Ku, Kobe, Hyogo, 650-0017, Japan.
2 Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-Chzo, Chuo-Ku, Kobe, Hyogo, 650-0017, Japan. asakai@med.kobe-u.ac.jp.
3 Division of Diagnostic Pathology, Kobe University Graduate School of Medicine, Hyogo, Japan.
4 Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Hyogo, Japan.