Holocord pylocitic astrocytoma associated to syringomyelia J. Trillo-Tinoco * , T. Garibay-Huarte, E. Gómez-Apo, M. A. Rodríguez-Florido, L. Chávez-Macias, J. E. Olvera-Rabiela * Hospital General de Mexico, Dept. of Surgical Pathology, Mexico City, Mexico