1. Department of Surgery; Graduate School of Medicine, Kyoto University; Kyoto Japan
2. Department of Gastroenterology; Graduate School of Medicine, Kobe University; Hyogo Japan
3. Department of Gastroenterology and Hepatology; Graduate School of Medicine, Kyoto University; Kyoto Japan
4. Department of Diagnostic Pathology; Graduate School of Medicine, Kyoto University; Kyoto Japan