1. Department of Surgery, Isesaki Municipal Hospital, Japan
2. Department of Pathology, Japanese Red Cross Kyoto Daini Hospital, Japan
3. Department of Radiology, Isesaki Municipal Hospital, Japan
4. Department of Pathology, Isesaki Municipal Hospital, Japan
5. Department of Gastroenterology, Isesaki Municipal Hospital, Japan
6. Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgical Science, Graduate School of Medicine, Gunma University, Japan