title: Lipomatous hemangiopericytoma of the skull base and parapharyngeal space.
abstract: OBJECTIVE
  To discuss the diagnosis and clinical management of lipomatous hemangiopericytoma.
  
  
  METHODS
  Case report.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  A 36-year-old woman was encountered with symptoms of facial numbness, blurred vision, headache, and lightheadedness of 6 weeks' duration. Magnetic resonance imaging revealed a 5.0-cm mass in the right parapharyngeal space and skull base extending inferiorly to the level of the carotid bifurcation. The mass was consistent radiographically with a glomus jugulare tumor, and surgical extirpation was performed.
  
  
  METHODS
  The patient underwent a transtemporal approach to the right posterior fossa and jugular foramen including mastoidectomy and isolation and preservation of Cranial Nerves VII, X, XI, and XII. Microscopic analysis of the mass revealed a highly cellular spindled mesenchymal tumor with a pericytoma pattern. Almost half of the mass displayed a mature lipomatous component. These findings were consistent with a lipomatous hemangiopericytoma.
  
  
  RESULTS
  The authors describe the first case of lipomatous hemangiopericytoma involving the skull base. This rare variant of the more common hemangiopericytoma has been described previously in the retroperitoneal and lower extremities. Although one case of lipomatous hemangiopericytoma has been described in the occipital region, this is the first report of this entity involving the parapharyngeal space, skull base, and jugular foramen.
  
  
  CONCLUSIONS
  The authors demonstrate that lipomatous hemangiopericytoma can occur in the parapharyngeal space and skull base. Once thought to be an aggressive variant, this tumor has an extremely low propensity for distant or local recurrence. Adjuvant therapies such as radiation and chemotherapeutic agents are reserved for recurrent or metastatic lesions.
authors.affiliation: Michigan Ear Institute, Farmington Hills 48377, Department of Neurotology and Skull Base Surgery, Providence Hospital Medical Center, Southfield, and Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA.
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Shaia
authors.forename: Dennis I
authors.initials: DI
authors.lastname: Bojrab
authors.forename: Seilesh
authors.initials: S
authors.lastname: Babu
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Pieper
mesh_terms: D003937:Diagnosis, Differential; D004584:Electronystagmography; D005260:Female; D005925:Glomus Jugulare Tumor / Q000175:diagnosis; D006261:Headache; D006393:Hemangiopericytoma / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008416:Mastoid / Q000601:surgery; D008875:Middle Aged; D009759:Nystagmus, Pathologic; D019292:Skull Base Neoplasms / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome