title: Presentation of a minimally symptomatic large extradural hematoma in a patient with an arachnoid cyst: a case report and review of the literature.
abstract: BACKGROUND
  Hemorrhagic complications of arachnoid cysts have been reported, extensively presenting with subdural or intracystic hematoma after trauma, but presentation with extradural hemorrhage is very rare. In this paper, we report the case of a patient with an arachnoid cyst who developed an extradural hematoma after a subtle head injury. Our patient presented with very mild symptoms in spite of the very large size of the hematoma.
  
  
  METHODS
  Our patient was a 23-year-old Iranian man who complained of diffuse progressive headache and vomiting after mild head trauma. A brain computerized scan showed a very large extradural hematoma in the left frontotemporoparietal convexity over a large arachnoid cyst.
  
  
  CONCLUSIONS
  Brain parenchyma containing an arachnoid cyst is vulnerable to trauma and increases the risk of serious hemorrhagic complications. We also suggest that the abnormal shape of the head should be considered as an indication for a computerized tomography scan in cases of mild head injury.
authors.affiliation: Functional Neurosurgery Research Center of Shohada Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. a_sedighi@sbmu.ac.ir.
authors.forename: Afsoun
authors.initials: A
authors.lastname: Seddighi
authors.forename: Amir Saied
authors.initials: AS
authors.lastname: Seddighi
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Zali
authors.forename: Hesam Rahimi
authors.initials: HR
authors.lastname: Baqdashti