title: Pathology of spinal ependymomas: an institutional experience over 25 years in 134 patients.
abstract: BACKGROUND
  Ependymomas constitute approximately 40% of primary intraspinal tumors. Current World Health Organization (WHO) grading may not correlate with observed progression-free survival (PFS).
  
  
  OBJECTIVE
  This retrospective study of prospectively collected data examines whether PFS is influenced by the histological grade or by the extent of resection. It also analyzes the usage and effectiveness of postoperative adjuvant radiotherapy.
  
  
  METHODS
  We reviewed 134 consecutive patients with ependymomas of all grades. Pathology slides were re-reviewed and the histological grades were confirmed by a single neuropathologist. Postoperative residual or recurrence was evaluated with follow-up magnetic resonance imaging.
  
  
  RESULTS
  There were 85 male and 49 female patients, ranging from 10 to 79 (median 41) years of age. Thirty patients had WHO grade I tumors, 101 had grade II tumors, and 3 had grade III tumors. Kaplan-Meier analysis of PFS demonstrated a mean duration of 6 years for grade I, 14.9 years for grade II, and 3.7 years for grade III (P < .001). In grade II ependymomas, mean PFS was 11.2 years with subtotal resection and 17.8 years with gross total resection (P < .01). PFS of patients who underwent subtotal resection was not significantly changed by adjuvant radiotherapy (P < .36).
  
  
  CONCLUSIONS
  Patients with grade II ependymoma have significantly longer PFS than patients with grade I ependymoma. The extent of resection did not affect PFS in grade I ependymoma but it did in grade II. Contrary to its higher grade, WHO grade II ependymoma carries a better prognosis than WHO grade I ependymoma.
authors.affiliation: *Department of Neurosurgery, University of California, San Francisco, San Francisco, California; ‡Department of Pathology, University of California, San Francisco, San Francisco, California.
authors.forename: Phiroz E
authors.initials: PE
authors.lastname: Tarapore
authors.forename: Peter
authors.initials: P
authors.lastname: Modera
authors.forename: Agne
authors.initials: A
authors.lastname: Naujokas
authors.forename: Michael C
authors.initials: MC
authors.lastname: Oh
authors.forename: Beejal
authors.initials: B
authors.lastname: Amin
authors.forename: Tarik
authors.initials: T
authors.lastname: Tihan
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Parsa
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.forename: Dean
authors.initials: D
authors.lastname: Chou
authors.forename: Praveen V
authors.initials: PV
authors.lastname: Mummaneni
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Weinstein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D018572:Disease-Free Survival; D004806:Ependymoma / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology; D019635:Neurosurgical Procedures; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D016896:Treatment Outcome; D055815:Young Adult