1. Division of Gastroenterology, Department of Internal Medicine, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan
2. Department of Hematology, Department of Internal Medicine, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan
3. Department of Diagnostic Pathology, Showa University Fujigaoka Hospital, Yokohama, Kanagawa Japan