title: Chondrosarcoma of the skull base: long-term follow-up.
abstract: OBJECTIVE
  Chondrosarcoma of the skull base is an uncommon neoplasm comprising 0.15% of all intracranial tumors and 6% of skull base neoplasms. The outcome of treatment is difficult to assess because the slow growth rate means that there is a long interval before detecting the recurrence. We describe the use of lateral skull base techniques for these lesions and examine the long-term outcomes. The pathological features, radiological findings, and radiotherapy options are also discussed.
  
  
  METHODS
  Retrospective case review with current follow-up where possible.
  
  
  METHODS
  Tertiary referral neurotologic private practice.
  
  
  METHODS
  Eight patients with histologically confirmed skull base chondrosarcoma operated on since 1979. At the time of the surgery, the five women and three men ranged in age from 31 to 63 years, with a mean of 42.9 years. The follow-up ranged from 9 months to 25 years and 5 months.
  
  
  METHODS
  All patients underwent surgical removal; the earliest patient underwent surgical removal via transcochlear and retrosigmoid approaches, and seven via an infratemporal fossa approach, with or without exenteration of the otic capsule.
  
  
  METHODS
  Number of patients with residual and recurrent tumors.
  
  
  RESULTS
  In the patient who underwent surgery via the transcochlear approach, recurrence was noted within 3 months, and new exploration using the retrosigmoid approach was performed for the removal of the recurrent lesion. This patient showed no signs of recurrence for 25 years since last surgery. Of the seven patients who underwent surgery via the infratemporal fossa approach, one had residual tumor found at 1 year, but remained alive and well for 21 years after the surgery. The other six had gross total resection and showed no signs of recurrence at the last known follow-up. One patient died as a result of an unrelated cause 18 years after surgery for the chondrosarcoma.
  
  
  CONCLUSIONS
  The gross total resection of these lesions is possible because of the evolution of lateral skull base techniques and can be routinely accomplished with the infratemporal fossa approach. The improved exposure afforded by this approach seems to have resulted in more complete extirpation of the tumor and a decrease in the recurrence rate.
authors.affiliation: University of Southern California, Los Angeles, California, USA. dbrackmann@hei.org
authors.forename: Derald E
authors.initials: DE
authors.lastname: Brackmann
authors.forename: Karen Borne
authors.initials: KB
authors.lastname: Teufert
mesh_terms: D000328:Adult; D002813:Chondrosarcoma / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D004432:Ear, Middle; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D018365:Neoplasm, Residual; D010579:Petrous Bone; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D019291:Skull Base / Q000601:surgery*; D019292:Skull Base Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome