1. Kwandong Graduate School of Medicine; Gangneung-si Gangwon-do Korea
2. Department of Surgery; Yonsei University College of Medicine; 250, Seongsanno, Seodaemun-gu Seoul 120-752 Korea
3. Department of Surgery; Korea University College of Medicine; Seoul Korea
4. Department of Pathology; Yonsei University College of Medicine; Seoul Korea