title: Giant Spontaneous Epidural Pneumatocele: Case Report and Review of the Literature.
abstract: BACKGROUND
  Pneumocephalus is a commonly encountered finding in neurosurgery in which air displaces intracranial cerebrospinal fluid after cranial surgery or a cerebrospinal fluid leak into paranasal or mastoid sinuses. When an intracranial air collection becomes chronically established in a fixed loculation causing mass effect, pneumatocele is a more appropriate term. We present an unusual case of a spontaneous giant frontotemporal epidural pneumatocele that persisted for more than 1 year before the patient presented for neurological treatment.
  
  
  METHODS
  A 40-year-old man with a remote history of minor head trauma presented with symptoms of headaches, dizziness, and vertigo. Imaging revealed a right giant epidural pneumocephalus secondary to bony dehiscence of the intracranial wall of the mastoid bone. A subtemporal middle fossa approach was performed to repair the mastoid defect with hydroxyapatite, fat graft, and temporalis fascia. The patient was discharged on postoperative day 2 with improvement in his headaches. One month after discharge operative imaging demonstrated complete resolution of his epidural pneumatocele and improvement in his headaches.
  
  
  CONCLUSIONS
  This unique case represents the first reported case in the neurosurgical literature of a giant spontaneous epidural pneumatocele occurring in an adult treated with a middle fossa approach with resolution on follow-up imaging.
authors.affiliation: Department of Neurological Surgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Krisht
authors.affiliation: Department of Neurological Surgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Ilyas M
authors.initials: IM
authors.lastname: Eli
authors.affiliation: Department of Pathology, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Cheryl Ann
authors.initials: CA
authors.lastname: Palmer
authors.affiliation: Department of Neurological Surgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA. Electronic address: richard.schmidt@hsc.utah.edu.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D065634:Cerebrospinal Fluid Leak / Q000601:surgery; D035301:Cranial Fossa, Middle / Q000601:surgery; D004824:Epidural Space / Q000473:pathology / Q000601:surgery*; D006261:Headache / Q000209:etiology; D006801:Humans; D008297:Male; D008416:Mastoid / Q000473:pathology; D019635:Neurosurgical Procedures / Q000379:methods*; D011007:Pneumocephalus / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Hyperpneumatization; Pneumatocele; Pneumocephalus