title: Endoscopic endonasal resection of skull base chondrosarcomas: technique and early results.
abstract: OBJECTIVE
  The authors of this study sought to report the technique and early clinical outcomes of a purely endonasal endoscopic approach for resection of petroclival chondrosarcomas.
  
  
  METHODS
  Between 2010 and 2014, 8 patients (4 men and 4 women) underwent endonasal endoscopic operations to resect petroclival chondrosarcomas at 2 institutions. The patients' mean age was 44.8 years (range 30-64 years). One of the patients had previously undergone radiation therapy and another a staged craniotomy. Using volumetric software, an independent neuroradiologist assessed the extent of the resections on MRI scans taken immediately after surgery and at the 3-month follow-up. Immediate complications and control of symptoms were also recorded. In addition, the authors reviewed the current literature on surgical treatment of chondrosarcoma.
  
  
  RESULTS
  The mean preoperative tumor diameter and volume were 3.4 cm and 9.8 cm(3), respectively. Six patients presented with cranial neuropathies. Endonasal endoscopic surgery achieved > 95% resection in 5 of the 8 patients and < 95% resection in the remaining 3 patients. One of the 6 neuropathies resolved, and the remaining 5 partially improved. One instance of postoperative CSF leakage required a reoperation for repair; no other complications associated with these operations were observed. All of the patients underwent adjuvant radiotherapy.
  
  
  CONCLUSIONS
  According to the authors' experience, the endoscopic endonasal route is a safe and effective approach for the resection of appropriately selected petroclival chondrosarcomas.
authors.affiliation: Departments of 1 Neurological Surgery.
authors.forename: Nelson
authors.initials: N
authors.lastname: Moussazadeh
authors.forename: Charles
authors.initials: C
authors.lastname: Kulwin
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Anand
authors.forename: Jonathan Y
authors.initials: JY
authors.lastname: Ting
authors.forename: Caryn
authors.initials: C
authors.lastname: Gamss
authors.forename: J Bryan
authors.initials: JB
authors.lastname: Iorgulescu
authors.forename: Apostolos John
authors.initials: AJ
authors.lastname: Tsiouris
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Cohen-Gadol
authors.forename: Theodore H
authors.initials: TH
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D002813:Chondrosarcoma / Q000601:surgery*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods*; D019292:Skull Base Neoplasms / Q000601:surgery*; D016896:Treatment Outcome
keywords: chondrosarcoma; clivus; minimally invasive; neuroendoscopy; oncology; petrous apex; pituitary surgery; skull base; transpterygoid approach