1. Yonsei University College of Medicine, Severance Hospital, Yonsei University Health System , Seoul 03722, The Republic of Korea
2. Department of Pathology , Severance Hospital, , Seoul 03722, The Republic of Korea
3. Yonsei University College of Medicine , Severance Hospital, , Seoul 03722, The Republic of Korea
4. Department of Hepatobiliary and Pancreatic Surgery, Yonsei University College of Medicine , Seoul 03722, The Republic of Korea