title: Computed tomography and magnetic resonance features of extraventricular neurocytoma: a study of eight cases.
abstract: OBJECTIVE
  To present the neuroradiological and clinical findings of extraventricular (central) neurocytomas (EVNs) to increase awareness of this entity.
  
  
  METHODS
  The computed tomography (CT; n = 6), magnetic resonance imaging (MRI; n = 8), and clinical presentations of eight patients with pathologically documented EVN were retrospectively analysed.
  
  
  RESULTS
  Most tumours were well circumscribed and occurred in young adults. Six tumours were solid or solid-cystic, five of these showed contrast enhancement and three contained calcifications. Multiple small cysts were present in one solid mass and had a "soap bubble" or spongy appearance on MRI. Two other tumours were predominantly cystic; these demonstrated slight contrast enhancement, which contained calcifications. Of the six cases assessed using CT, three showed predominantly hyperdensity and three showed hypodensity, with a mean attenuation value of 75 HU. At MRI, eight masses were isointense (n = 4) or hypointense (n = 4) to grey matter on T1-weighted images and hyperintense (n = 6), isointense (n = 1), or hypointense (n = 1) on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. Signal voids were visible in two cases. Four tumours had mild or moderate peritumoural oedema.
  
  
  CONCLUSIONS
  EVN is a rare neoplasm that can have significant overlap in imaging appearance with other primary brain neoplasms; therefore, it is difficult to make an accurate preoperative diagnosis. However, EVN should be considered in the differential diagnosis when a large cerebral parenchymal mass with cystic change and calcification is encountered in younger patients.
authors: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors: W-Y
authors: WY
authors: Huang
authors: B-Y
authors: BY
authors: Zhang
authors: D-Y
authors: DY
authors: Geng
authors: J
authors: J
authors: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001931:Brain Mapping / Q000379:methods; D001932:Brain Neoplasms / Q000150:complications / Q000175:diagnosis*; D002114:Calcinosis / Q000150:complications / Q000175:diagnosis; D002648:Child; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007472:Iohexol; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018306:Neurocytoma / Q000150:complications / Q000175:diagnosis*; D015588:Observer Variation; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; D019786:Gadolinium DTPA