title: Atypical extensive extratemporal hyperpneumatization of the skull base including the cervical spine: case report and review of the literature.
abstract: METHODS
  Case report and clinical discussion.
  
  
  OBJECTIVE
  To describe a rare case of hyperpneumatization of the skull base including the cervical spine with the atlas bone.
  
  
  BACKGROUND
  Initial imaging studies of physically traumatized patients consist of conventional radiographs. An atypical radiolucency is often misdiagnosed as a primary malignancy or a secondary osteolytic metastasis. Further imaging studies may reveal an underlying atypical hyperpneumatization as a very rare benign differential diagnosis. Pathophysiologically, embryological developmental anomalies as well as an elevated pressure to the middle and inner ear are discussed.
  
  
  METHODS
  We present a symptomatic 40-year-old man with conventional radiographs, after computed tomography and magnetic resonance imaging examinations.
  
  
  RESULTS
  Imaging studies reveal an uncommon radiolucency of the skull base including the atlas bone, free air beneath the mastoid bone, stylomastoid foramen, epidural air adjacent to the atlas bone, and surrounding soft-tissue emphysema.
  
  
  CONCLUSIONS
  Atypical radiolucency may represent a very rare benign hyperpneumatization of the skull base, which may include the craniocervical junction. Because of microfractures of the thinned and consecutive, less stable bones, this also can lead to free air and soft-tissue emphysema, which has not been described previously. Special care should be taken to identify epidural free air because of a possible communication of the epidural space with the external environment. Harmful activities and especially high-speed trauma could result in fractures of the cervical spine due to decreased stability of the hyperpneumatized bones.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Saarland University Hospital, Homburg/Saar, Germany. Alexander.Massmann@uks.eu
authors.forename: Alexander
authors.initials: A
authors.lastname: Massmann
authors.forename: Patric
authors.initials: P
authors.lastname: Garcia
authors.forename: Antonius
authors.initials: A
authors.lastname: Pizanis
authors.forename: Christian
authors.initials: C
authors.lastname: Roth
authors.forename: Christian
authors.initials: C
authors.lastname: Nieder
authors.forename: Günther
authors.initials: G
authors.lastname: Schneider
authors.forename: Arno
authors.initials: A
authors.lastname: Bücker
mesh_terms: D000328:Adult; D001847:Bone Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D001270:Cervical Atlas / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D009777:Occipital Bone / Q000000981:diagnostic imaging* / Q000473:pathology; D011007:Pneumocephalus / Q000000981:diagnostic imaging*; D011859:Radiography; D019291:Skull Base / Q000000981:diagnostic imaging* / Q000473:pathology; D013701:Temporal Bone / Q000000981:diagnostic imaging* / Q000473:pathology