1. Department of Pathology, Keio University School of Medicine, Tokyo, Japan
2. Department of Surgery, Keio University School of Medicine, Tokyo, Japan
3. Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan
4. Department of Surgery, Kawasaki Municipal Hospital, Kanagawa, Japan
5. Department of Surgery, Hachioji Medical Center, Tokyo Medical University, Tokyo, Japan