[1] Univ Med Ctr Freiburg, Dept Pediat & Adolescent Med, Div Pediat Hematol & Oncol, Freiburg, Germany
[2] Univ Med Ctr Freiburg, Dept Pediat & Adolescent Med, Div Gen Pediat, Freiburg, Germany
[3] Univ Med Ctr Freiburg, Dept Pediat & Adolescent Med, Div Pediat Hematol & Oncol ogy, Mathildenstr 1, D-79106 Freiburg, Germany
[4] Shanghai Jiao Tong Univ, Renji Hosp, Sch Med, Dept Biliary Pancreat Surg, Shanghai, Peoples R China