1. Department of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
2. Department of Obstetrics and Gynecology, Iwate Medical University, Yahaba 028-3695, Japan
3. Department of Gynecologic Oncology, National Hospital Organization Shikoku Cancer Center, Matsuyama 791-0280, Japan
4. Department of Gynecologic Oncology, Hyogo Cancer Center, Akashi 673-8558, Japan
5. Department of Obstetrics and Gynecology, Tohoku University, Sendai 980-8574, Japan
6. Department of Obstetrics and Gynecology, Kurume University School of Medicine, Kurume 830-0011, Japan
7. Department of Obstetrics and Gynecology, Jichi Medical University, Shimotsuke 329-0498, Japan
8. Department of Obstetrics and Gynecology, Hirosaki University, Hirosaki 036-8562, Japan
9. Department of Pathology, Matsue City Hospital, Matsue 690-8509, Japan
10. Department of Pathology, National Hospital Organization Shikoku Cancer Center, Matsuyama 791-0280, Japan
11. Department of Diagnostic Pathology, Kumamoto University, Kumamoto 860-8556, Japan
12. Matsue City Hospital, Matsue 690-8509, Japan