Erratum to: Acta Neurochir

DOI 10.1007/s00701-009-0253-1

Two of the patients in this paper were included in a recent publication in the radiological literature on this subject: Nguyen et al. (2009) Extraosseous chordoma of the nasopharynx. AJNR Am J Neuroradiol. doi:10.3174/ajnr.A1446.