title: Isolated orbital fibrous dysplasia associated with ipsilateral keratoconus.
abstract: BACKGROUND
  Fibrous dysplasia is a primary orbital bone tumor, described as a benign disorder in which proliferation of fibrous tissue and osteoid replaces and distorts the bone from which it derives. Unilateral keratoconus is a rare entity. Herein, we report a case of an extensive ethmoidal fibrous dysplasia associated with ipsilateral keratoconus, and review the literature on the subject.
  
  
  METHODS
  A 22-year-old man presented with left painless proptosis evolving over 10 years. There was associated ipsilateral epiphora and gradual visual loss. On examination his visual acuity was 20/20 OD and CF OS. His left globe was displaced lateraly 12 mm, with 9 mm of proptosis. The extraocular movements were normal. Left nasolacrimal duct obstruction was noted. Clinical signs of keratoconus were present only in the left cornea. High resolution corneal topography confirmed unilateral keratoconus and a CT scan showed an ovoid mass with a well defined sclerotic margin arising from the left ethmoid sinus and invading the orbit.
  
  
  RESULTS
  The patient underwent resection of the lesion via a modified Lynch incision. Complete regression of proptosis was observed immediately after surgery. Histopathological examination revealed irregular trabeculae of woven bone in different levels of maturation in a moderately cellular fibrous matrix without nuclear atypia. Trabeculae were without osteoblastic rimming or osteoclastic resorption. There has been no recurrence over a 2-year follow-up period.
  
  
  CONCLUSIONS
  To our knowledge, the coexistence of unilateral isolated craniofacial fibrous dysplasia with ipsilateral keratoconus has not been reported so far.
authors.affiliation: Department of Ophthalmology, Metropolitan Hospital, Athens, Greece.
authors.forename: Vasilios S
authors.initials: VS
authors.lastname: Liarakos
authors.forename: Luca
authors.initials: L
authors.lastname: Ilari
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Chalvatzis
authors.forename: Kleio
authors.initials: K
authors.lastname: Papaparaskeva
authors.forename: Ioannis
authors.initials: I
authors.lastname: Mavrikakis
mesh_terms: D001707:Biopsy, Needle; D005005:Ethmoid Sinus / Q000473:pathology / Q000601:surgery; D005094:Exophthalmos / Q000175:diagnosis / Q000209:etiology; D005357:Fibrous Dysplasia of Bone / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007640:Keratoconus / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D007766:Lacrimal Apparatus Diseases / Q000175:diagnosis / Q000209:etiology; D008297:Male; D009915:Orbit / Q000473:pathology* / Q000601:surgery; D035583:Rare Diseases; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology; D055815:Young Adult