1. Division of Neurosurgery - Department of Surgery, Gaffrée e Guinle University Hospital, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil,
2. Gaffrée e Guinle University Hospital, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil,
3. Pathology Department, Antônio Pedro University Hospital, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil,
4. A. C. Camargo Câncer Center, São Paulo, São Paulo, Brazil.