title: Solitary fibrous tumor of the orbit with extraorbital extension: case report.
abstract: OBJECTIVE
  Solitary fibrous tumors (SFTs) are rare tumors of mesenchymal origin that typically arise in the pleura. Only 24 cases of SFTs in the orbit have been reported, all located within the orbit and generally with a benign course. We report the first case of an orbital SFT with extraorbital extension and short-term regrowth.
  
  
  METHODS
  A 54-year-old man presented with proptosis and double vision that had persisted for 7 months. The tumor extended from the right extraconal inferolateral orbit to the extradural middle cranial fossa and cavernous sinus, via the superior orbital fissure, on magnetic resonance imaging scans. Positron emission tomography with [(18)F]fluorodeoxyglucose demonstrated faint uptake in the orbital portion.
  
  
  METHODS
  Resection of the tumor was performed twice, because of short-term regrowth of the residual tumor in the orbit. The histological diagnosis was a SFT. The MIB-1 labeling index was 7% and the mitotic count was 5 mitotic figures/10 high-power fields at the time of the second operation. These findings indicate the malignant nature of the tumor.
  
  
  CONCLUSIONS
  The natural history of SFTs of the orbit remains unclear, and the importance of careful and continued follow-up monitoring of the tumor should be emphasized.
authors.affiliation: Department of Neurosurgery, Gunma University School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. n-ringo@mba.sphere.ne.jp
authors.forename: S
authors.initials: S
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Kurihara
authors.forename: J
authors.initials: J
authors.lastname: Hirato
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D002426:Cavernous Sinus / Q000473:pathology / Q000601:surgery; D005350:Fibroma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018365:Neoplasm, Residual / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D009915:Orbit / Q000473:pathology / Q000601:surgery; D009918:Orbital Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D012086:Reoperation