[1] Natl Ctr Child Hlth & Dev, Childrens Canc Ctr, Div Leukemia & Lymphoma, Tokyo, Japan
[2] Saiseikai Yokohama City South Hosp, Dept Pediat, Yokohama, Kanagawa, Japan
[3] St Marianna Univ, Sch Med, Dept Pediat, Kawasaki, Kanagawa, Japan
[4] Kyushu Natl Canc Ctr, Dept Pediat, Fukuoka, Japan
[5] Ama City Hosp, Dept Pediat, Jimokuji, Aichi, Japan
[6] Kurume Univ, Sch Med, Dept Pathol, Fukuoka, Japan
[7] Natl Ctr Child Hlth & Dev, Dept Pathol, Tokyo, Japan
[8] Sapporo Hokuyu Hosp, Dept Pediat, Sapporo, Hokkaido, Japan