title: Surgery for primary filum terminale ependymomas: outcome and prognostic factors.
abstract: BACKGROUND
  Primary filum terminale ependymoma (PFTE) is a unique type of ependymomas and locates on extramedullary site. However, the clinical features and prognostic factors of PFTE are still unknown due to its rarity.
  
  
  OBJECTIVE
  This study aimed to evaluate the clinical features, outcomes, and prognostic factors of PFTE in the largest series of cases.
  
  
  RESULTS
  Thirty-eight patients were included in this study. Gross total removal (GTR) of the tumors was achieved in 33(87%) patients. Five (13%) patients had subtotal resection (STR). For the residual tumors, postoperative radiotherapy increased the interval between the first surgery and tumor regrowth (P = 0.063). Six patients had local recurrence/progression. Univariate analysis identified STR(P = 0.001), unencapsulated tumor (P = 0.018), tumor involving more than two vertebral columns (P = 0.005), and tumor invading sacral canal(P < 0.001) as predictors of tumor recurrence. In addition, 36 (95%) patients had stable or improved neurological status directly after surgery. Klekamp-Samii score was better correlated with the symptoms than McCormick scale.
  
  
  CONCLUSIONS
  Extent of surgical removal, tumor size, tumor location, and the integrity of tumor capsule are the prognostic factors of PFTEs, and the intrasacral PFTEs always have a poor prognosis.
authors.affiliation: Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Tian-Hao
authors.initials: TH
authors.lastname: Xie
authors.forename: Xian-Zhen
authors.initials: XZ
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Qian
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Lu
authors.forename: Yi-Kun
authors.initials: YK
authors.lastname: Jiang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Guo-Han
authors.initials: GH
authors.lastname: Hu
authors.forename: Xue-Hua
authors.initials: XH
authors.lastname: Ding
authors.forename: Chun
authors.initials: C
authors.lastname: Luo
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002420:Cauda Equina / Q000473:pathology*; D004806:Ependymoma / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010524:Peripheral Nervous System Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: Outcome; Primary filum terminale ependymoma; Prognostic factor; Surgery