title: Ocular adnexal (orbital) solitary fibrous tumor: nuclear STAT6 expression and literature review.
abstract: OBJECTIVE
  To report the clinico-pathological features of solitary fibrous tumor occurring in the ocular adnexa (OA) in a single center. To assess the presence of NAB2-STAT6 genes fusion in OA solitary fibrous tumor detected by nuclear overexpression of STAT6.
  
  
  METHODS
  Retrospective study including orbital and OA solitary fibrous tumors treated between 2006 and 2014 in our center. The clinical, radiological, and histopathological findings were evaluated. STAT6 expression was assessed by immunohistochemistry.
  
  
  RESULTS
  Five patients were identified and presented with a chronic OA mass. The tumors were radiologically well delimited, highly vascularized and without bone erosion. All the patients underwent complete surgical excision. Pathological examination confirmed solitary fibrous tumor in all cases. All tumors demonstrated a nuclear expression of STAT6. There were no recurrences, with a mean follow-up of 5 years after surgery. Our review demonstrated that proptosis was the most common presentation occurring in 60 % of the cases. In the ocular adnexa, adverse histological criteria were found in 19.7 % of the tumors, and recurrences were observed in 48 % of these cases. Thirty-six percent of patients presented at least one local recurrence, and metastastic spread was found in 2.4 % of the cases. Tumor-related death was described in two cases.
  
  
  CONCLUSIONS
  Ocular adnexal SFT are rare and usually present as a chronic orbital mass with proptosis. In the OA, solitary fibrous tumor demonstrates STAT6 nuclear expression, as documented in other locations. Recurrences are unusual and metastasis exceptional. Initial surgical resection should be complete in order to avoid recurrence.
authors.affiliation: Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, 15 Avenue de France, 1004, Lausanne, Switzerland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Petrovic
authors.forename: Aurélie
authors.initials: A
authors.lastname: Obéric
authors.forename: Alexandre
authors.initials: A
authors.lastname: Moulin
authors.forename: Mehrad
authors.initials: M
authors.lastname: Hamedani
mesh_terms: D000328:Adult; D000368:Aged; D005094:Exophthalmos / Q000175:diagnosis; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008279:Magnetic Resonance Imaging; D008297:Male; D013508:Ophthalmologic Surgical Procedures; D009918:Orbital Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D012189:Retrospective Studies; D050800:STAT6 Transcription Factor / Q000378:metabolism*; D054364:Solitary Fibrous Tumors / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D014792:Visual Acuity
chemical_list: D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human