title: Intradural cranial chordoma.
abstract: BACKGROUND
  Intradural chordomas are rare and have been considered benign owing to the feasibility of complete resection and the display of lesser aggressive biologic behavior than typical chordomas.
  
  
  METHODS
  We herein reported 2 cases of intradural cranial chordoma with aggressive biologic behavior. A tumor (anti-Ki-67 monoclonal antibody [MIB-1], 13.9%) in a 59-year-old woman was strongly adherent to the brainstem and involved the basilar artery and its branches. After subtotal removal, the remnant tumor was treated with stereotactic radiotherapy. A tumor (MIB-1, 6.2%) in a 75-year-old woman repeatedly recurred even after initial gross total removal. The recurrent chordomas were treated with γ-knife radiosurgery.
  
  
  CONCLUSIONS
  The cases presented in this study indicate that intradural chordomas can also be aggressive such as typical chordomas. Long-term follow-ups with a large number of patients with this condition are essential for elucidating the prognosis of intradural chordomas.
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Ito
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Saito
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nagatani
authors.forename: Junzo
authors.initials: J
authors.lastname: Ishiyama
authors.forename: Koichi
authors.initials: K
authors.lastname: Terada
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Wakabayashi
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D002817:Chordoma / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D004388:Dura Mater; D005260:Female; D006801:Humans; D008875:Middle Aged; D016634:Radiosurgery