title: "Volcano sign"--description of a sign of aggressive neoplastic epidural lesions with subdural extension.
abstract: BACKGROUND
  Aggressive epidural intracranial lesions that break through the dura and develop an intra-axial component have been well-described previously in literature. However, there is no description of lesions with an epidural component and an exclusive subdural component without parenchymal extension in the pediatric patient.
  
  
  CONCLUSIONS
  We have noticed a characteristic sign on cross-sectional imaging studies that indicates dural breakthrough resulting in a large extradural component and second subdural component, but no extraparenchymal component. This is best described as a "volcano sign" which characterizes the appearance caused by a focal break in the dural lining resulting in a sizeable subdural component from rapid lesion growth. In the pediatric patient, this sign is characteristic of a rapidly growing sarcomatous lesion, either primary or secondary.
authors.affiliation: Department of Radiology, Children's Hospital Boston and Harvard Medical School, 300 Longwood Avenue, Boston, MA, USA. sanjay.prabhu@childrens.harvard.edu
authors.forename: Sanjay P
authors.initials: SP
authors.lastname: Prabhu
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D004388:Dura Mater / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D018316:Gliosarcoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D012516:Osteosarcoma / Q000473:pathology* / Q000556:secondary; D012512:Sarcoma, Ewing / Q000473:pathology* / Q000556:secondary; D013355:Subdural Space / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed