[1] Southern Illinois Univ, Sch Med, Dept Gen Surg, Div Surg, Springfield, IL 62702 USA
[2] Seattle Childrens Hosp, Canc & Blood Disorders Ctr, Seattle, WA 98195 USA
[3] Univ Washington, Sch Med, Dept Pediat, Div Hematol & Oncol, Seattle, WA 98195 USA
[4] St Jude Childrens Res Hosp, Dept Pathol, Memphis, TN 38105 USA
[5] St Jude Childrens Res Hosp, Dept Surg, Memphis, TN 38105 USA
[6] Univ Tennessee, Hlth Sci Ctr, Dept Surg, Div Pediat Surg, Memphis, TN 38105 USA