1. Department of Pathology, Instituto Nacional de Pediatría, Insurgentes Sur #3700-C, Col. Insurgentes Cuicuilco, 04530, Mexico City, D.F., Mexico
2. Department of Neurosurgery, Instituto Nacional de Pediatría, Insurgentes Sur #3700-C, Col. Insurgentes Cuicuilco, 04530, Mexico City, D.F., Mexico