title: Primary haemangiopericytoma outside muscle cone in fossa orbitalis: a case report and review.
abstract: OBJECTIVE
  Orbital haemangiopericytoma (HPC) is a rare tumor with great histological variability and unpredictable clinical and biological behavior. The precise cell type origin is uncertain.
  
  
  METHODS
  A case report is provided.
  
  
  RESULTS
  A 24-year-old male patient visited an ophthalmologist because of proptosis, strabismus, and movement limitation of the right eye one year ago. These symptoms worsened rapidly. Histopathology, MRI methods and microscopy coil were applied to study the features of HPC. The tumor was removed and the histological examination revealed that it was a primary HPC of the orbit.
  
  
  CONCLUSIONS
  MRI determined the size, location, circumscription, morphological detail, growth pattern, and relationship between masses and surrounding tissues. The genesis location of this HPC was rare, and its internal morphological characters were different from cases reported in the literature. The new type of  microscope showed more details of tumor MR image characters objectively.
authors.affiliation: Department of Radiology,Guangdong NO.2 Provincial People's Hospital,Guangzhou 510317, China.
authors.forename: Jun Zhang
authors.initials: JZ
authors.lastname: Tian
authors.forename: Xiao Fen
authors.initials: XF
authors.lastname: Ma
authors.forename: Gui Hua
authors.initials: GH
authors.lastname: Jiang
authors.forename: Jin
authors.initials: J
authors.lastname: Fang
authors.forename: Wen Feng
authors.initials: WF
authors.lastname: Zhan
mesh_terms: D005094:Exophthalmos / Q000209:etiology; D006393:Hemangiopericytoma / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009801:Oculomotor Muscles; D009918:Orbital Neoplasms / Q000473:pathology* / Q000601:surgery; D035583:Rare Diseases / Q000473:pathology* / Q000601:surgery; D017949:Retinal Cone Photoreceptor Cells; D013285:Strabismus / Q000209:etiology; D055815:Young Adult