1. Department of Gastroenterology, Tokyo-west Tokushukai Hospital, Japan
2. Department of Surgery, Tokyo-west Tokushukai Hospital, Japan
3. Department of Hepato-Biliary-Pancreatic Surgery, Shonan Kamakura General Hospital, Japan
4. Department of Gastroenterology, Saitama Sekishinkai Hospital, Japan
5. Department of Pathology, Tokyo-west Tokuhsukai Hospital, Japan