title: Huge intradural ossification caused by a mature spinal teratoma: case report.
abstract: OBJECTIVE
  Huge intradural ossifications in the spine are quite rare. We report for the first time a patient with a huge intradural ossification caused by a mature teratoma at the conus medullaris.
  
  
  METHODS
  A 68-year-old woman presented with low back pain and gait disturbance. Computed tomographic and magnetic resonance imaging revealed a huge ossification at the tip of the conus medullaris.
  
  
  METHODS
  We performed L1 and L2 laminectomy and removed the mass completely. The pathological diagnosis was mature teratoma with remarkable ossification.
  
  
  CONCLUSIONS
  This unusual case of intradural ossification demonstrated regressive changes in a mature teratoma. Despite its tight adhesion to the conus medullaris and cauda equina, the ossified tumor was atraumatically removed with an ultrasonic aspirator.
authors.affiliation: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. kosei2@m.kufm. kagoshima- u.ac.jp
authors.forename: Kosei
authors.initials: K
authors.lastname: Ijiri
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Hida
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yano
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Iwasaki
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009999:Ossification, Heterotopic / Q000209:etiology* / Q000601:surgery; D013115:Spinal Canal / Q000473:pathology*; D013116:Spinal Cord / Q000473:pathology*; D013125:Spinal Neoplasms / Q000150:complications* / Q000601:surgery; D013724:Teratoma / Q000150:complications* / Q000601:surgery