title: Osseous choristoma of the conjunctiva simulating extraocular extension of retinoblastoma.
abstract: OBJECTIVE
  To report the clinicopathologic features of an epibulbar osseous choristoma simulating extraocular extension of retinoblastoma.
  
  
  METHODS
  Interventional case report.
  
  
  METHODS
  A 7-month-old male presented with a unilateral intraocular mass localized to the temporal retina and a white pedunculated lesion extending from the conjunctiva, anterior to the insertion of the lateral rectus muscle. Clinical examination and computed tomography scan findings led to the diagnosis of retinoblastoma with extraocular extension. The child underwent excision of the epibulbar lesion and enucleation of the globe.
  
  
  RESULTS
  The histopathologic examination of the epibulbar lesion revealed an osseous choristoma. The intraocular contents displayed features typical of retinoblastoma without extraocular extension.
  
  
  CONCLUSIONS
  An epibulbar osseous choristoma can simulate extraocular extension of retinoblastoma in an eye harboring the intraocular malignancy.
authors.affiliation: Doheny Eye Institute and the Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.
authors.forename: Eduardo F
authors.initials: EF
authors.lastname: Marback
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Stout
authors.forename: Narsing A
authors.initials: NA
authors.lastname: Rao
mesh_terms: D001842:Bone and Bones; D002828:Choristoma / Q000175:diagnosis*; D003229:Conjunctival Diseases / Q000175:diagnosis*; D003937:Diagnosis, Differential; D015353:Eye Enucleation; D006801:Humans; D007223:Infant; D008297:Male; D019572:Retinal Neoplasms / Q000175:diagnosis*; D012175:Retinoblastoma / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed