1. Department of Hematology, Okayama City Hospital, Okayama-shi, Okayama, Japan,
2. Department of Hematology and Oncology, Okayama University Hospital, Okayama-shi, Okayama, Japan,
3. Department of Pathology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama-shi, Okayama, Japan,
4. Department of Pathology, Okayama City Hospital, Okayama-shi, Okayama, Japan