title: Long-term surgical outcomes of spinal meningiomas.
abstract: METHODS
  Retrospective case series.
  
  
  OBJECTIVE
  To evaluate the treatment strategies for spinal meningioma.
  
  
  BACKGROUND
  Although previous studies have demonstrated favorable surgical outcomes for spinal meningioma, with a low incidence of tumor recurrence, few have examined long-term surgical outcomes.
  
  
  METHODS
  The influence of patient age, surgical margin status (Simpson grade), tumor location, and histological subtype on tumor recurrence were examined retrospectively. In addition, the resected dura mater from Simpson grade I cases was examined for invasive tumor cells and compared with the presence or absence of a dural tail sign on magnetic resonance image.
  
  
  RESULTS
  Complete resection (Simpson grades I and II) was performed in 62 patients. Among them, the tumor recurrence rate was 9.7%, all in patients who underwent grade II resection for ventral spinal lesions. The mean duration to reoperation in these patients was 12.2 ± 5.2 years. Of the 6 patients who underwent incomplete resection (Simpson grade III/IV), all required reoperation for tumor recurrence or regrowth, 5 years later on average. Patients younger than 50 years at the initial surgery had a significantly higher recurrence rate than those aged 50 years or older. Histologic examination of 43 dura mater specimens from Simpson grade I-resection patients revealed tumor cell invasion between the inner and outer layers in 15 patients. This invasion was noted in 8 (29%) of 28 patients who were negative for the dural tail sign on magnetic resonance image, and in 7 (47%) of 15 patients who showed a positive dural tail sign. The MIB-1 index reached about 10% for dumbbell-type meningiomas invading the vertebral body; these were associated with repeated recurrence and unfavorable prognosis.
  
  
  CONCLUSIONS
  Long-term follow-up after surgery for meningiomas indicated that Simpson grade I resection should be selected whenever practicable when treating younger patients or dumbbell-type meningiomas. Tumors recurred at 12 years, on average, in approximately 30% of patients who underwent grade II resection.
authors.affiliation: Department of Orthopaedic Surgery, Keio University, Tokyo, Japan. masa@sc.itc.keio.ac.jp
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakamura
authors.forename: Osahiko
authors.initials: O
authors.lastname: Tsuji
authors.forename: Kanehiro
authors.initials: K
authors.lastname: Fujiyoshi
authors.forename: Naobumi
authors.initials: N
authors.lastname: Hosogane
authors.forename: Kota
authors.initials: K
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuji
authors.forename: Ken
authors.initials: K
authors.lastname: Ishii
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Chiba
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008577:Meningeal Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000453:epidemiology / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult