title: Clinical features and treatment outcome of chordoid meningiomas in a single institute.
abstract: OBJECTIVE
  Meningioma is the second most common primary central nervous system neoplasm. In contrast, chordoid meningioma is rare; due to the paucity of cases, little is known about its clinical features or treatment outcomes. The objectives of this study were to describe the clinical characteristics and outcomes for patients with chordoid meningioma.
  
  
  METHODS
  In total, 16 patients, with newly diagnosed chordoid meningioma who underwent surgical excision between 1999 and 2012 were included. We retrospectively evaluated the medical records, radiological findings, and pathological findings. The median follow-up period was 56.5 (range, 3-170) months. The MIB-1 labeling index ranged from 1 to 26.60% (median, 5.04).
  
  
  RESULTS
  Simpson grade I, II, and III resections were performed in four, nine, and three patients, respectively. The overall recurrence rate was 37.5%. Overall progression-free survival (PFS) after resection was 94.7 months (95% CI=62.9-126.6). Of the 4 patients with Simpson grade I resection, recurrence occurred in one patient. Among the Simpson grade II and III resection groups, eight patients underwent adjuvant radiation therapy and they showed significantly longer PFS (121 months, 95% CI=82.1-159.9) than the patients who underwent surgery alone (40.5 months, 95% CI=9.6-71.3) by the log-rank test (p<0.05).
  
  
  CONCLUSIONS
  Chordoid meningiomas are difficult to manage and have a high rate of recurrence. Complete resection of the tumor is a key determinant of better outcomes. Adjuvant radiation therapy is recommended, eparticulary when Simpson grade I resection was not achieved.
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Tae Keun
authors.initials: TK
authors.lastname: Jee
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyung-Il
authors.initials: KI
authors.lastname: Jo
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ho Jun
authors.initials: HJ
authors.lastname: Seol
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Doo-Sik
authors.initials: DS
authors.lastname: Kong
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Shin
keywords: Adjuvant radiation therapy; Chordoid meningioma; MIB-1 labeling index