title: Extraosseous chordoma of the nasopharynx.
abstract: OBJECTIVE
  Chordoma is a relatively rare tumor of the skull base and sacrum thought to originate from embryonic remnants of the notochord. Chordomas arising from the skull base/clivus are typically locally aggressive with lytic bone destruction. When chordomas occur in an extraosseous location, they may mimic other lesions of the nasopharynx. We present 5 cases of primarily extraosseous chordoma involving the nasopharynx in an effort to improve the preoperative diagnosis of this rare tumor. In addition, we review regional notochordal embryology to explain this variant tumor location.
  
  
  METHODS
  We reviewed the clinical and imaging data of 5 pathologically proved cases of extraosseous chordoma of the nasopharynx seen or reviewed at our institution during the last decade. All cases had both CT and MR imaging. The study had institutional review board approval.
  
  
  RESULTS
  The primary clinical complaint in the 5 patients with extraosseous nasopharyngeal chordoma was nasal obstruction. The extraosseous chordomas were centered in the nasopharynx. Bony lytic changes along the anterior surface of the clivus were seen on 5 of 5 CT studies. A midline sinus tract was seen in 3 of 5 patients. MR imaging showed heterogeneous hyperintense T2 signal intensity (5/5).
  
  
  CONCLUSIONS
  Extraosseous nasopharyngeal chordoma is a rare but important lesion to be considered in the differential diagnosis of nasopharyngeal masses. When a midline nasopharyngeal mass is found with an associated clival sinus tract, extraosseous chordoma moves to the top of the differential diagnosis list. Complete removal of the soft-tissue tumor and the clival sinus tract is the treatment of choice in such cases.
authors.affiliation: Department of Radiology, University of Utah Medical Center, Salt Lake City, Utah 84132, USA.
authors.forename: R P
authors.initials: RP
authors.lastname: Nguyen
authors.forename: K L
authors.initials: KL
authors.lastname: Salzman
authors.forename: H E
authors.initials: HE
authors.lastname: Stambuk
authors.forename: A T
authors.initials: AT
authors.lastname: Ahuja
authors.forename: H R
authors.initials: HR
authors.lastname: Harnsberger
mesh_terms: D000328:Adult; D000368:Aged; D002648:Child; D002817:Chordoma / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed