title: Primary Orbital Cystic Pilocytic Astrocytoma.
abstract: OBJECTIVE
  To describe the clinical, radiological and histopathological features of a highly unusual primary orbital glioma.
  
  
  METHODS
  A 6-year-old female presented with right-sided proptosis that revealed a well-defined intraconal mass on CT imaging with intact orbital bony walls. During the removal of the lesion, it dissected away freely from the muscles and was separated from the optic nerve and globe. There was no communication with the brain.
  
  
  RESULTS
  Histology showed histological features highly favouring a pilocytic astrocytoma enveloped by meninges. No non-neoplastic brain tissue was identified.
  
  
  CONCLUSIONS
  This is the first documentation of a primary orbital pilocytic astrocytoma not anatomically connected with the brain. We speculate that the tumour had arisen from developmental brain heterotopia.
authors.affiliation: National Specialist Ophthalmic Pathology Service (NSOPS), Department of Histopathology, Royal Hallamshire Hospital, Sheffield, UK.
authors.forename: Hardeep Singh
authors.initials: HS
authors.lastname: Mudhar
authors.affiliation: Chittagong Eye Infirmary and Training Complex, Chittagong, Bangladesh.
authors.forename: Murtuza
authors.initials: M
authors.lastname: Nuruddin
authors.affiliation: Chittagong Eye Infirmary and Training Complex, Chittagong, Bangladesh.
authors.forename: Soma
authors.initials: S
authors.lastname: Roy
keywords: Brain heterotopia; Orbit; Pilocytic astrocytoma; Primary