1. Department of Pathology; National Center for Child Health and Development; Tokyo Japan
2. Department of Pathology; Shizuoka Children's Hospital; Shizuoka Japan
3. Department of Pathology; Nagoya Daini Red Cross Hospital; Nagoya Japan
4. Division of Hematology and Oncology; Shizuoka Children's Hospital; Shizuoka Japan
5. Department of Pediatric Surgery; Shizuoka Children's Hospital; Shizuoka Japan
6. Department of Pathology; Keio University School of Medicine; Tokyo Japan