Affiliation: | 1.Division of Pediatric Oncology, Department of Pediatrics, Faculty of Medicine of Ribeir?o Preto,University of S?o Paulo,S?o Paulo,Brazil;2.Department of Pathology, Faculty of Medicine of Ribeir?o Preto,University of S?o Paulo,S?o Paulo,Brazil;3.Division of Neurosurgery, Department of Surgery and Anatomy, Faculty of Medicine of Ribeir?o Preto,University of S?o Paulo,S?o Paulo,Brazil;4.Hospital das Clínicas da Faculdade de Medicina de Ribeir?o Preto - USP. Laboratório de Pediatria,Ribeir?o Preto,Brazil |