1. Department of Hematology, Ibaraki Prefectural Central Hospital, Japan
2. Ibaraki Clinical Education and Training Center, University of Tsukuba Hospital, Japan
3. Faculty of Medicine, University of Tsukuba, Japan
4. Department of Medical Oncology, Ibaraki Prefectural Central Hospital, Japan
5. Department of Pathology, Ibaraki Prefectural Central Hospital, Japan