title: Imaging features of rosette-forming glioneuronal tumours (RGNTs): A Series of seven cases.
abstract: OBJECTIVE
  Rosette-forming glioneuronal tumours (RGNTs) are a recently described, rare, distinct nosological entity of the glioneuronal family. We describe imaging findings (CT and MRI) in seven patients with RGNTs.
  
  
  METHODS
  This retrospective study includes seven RGNT patients (4 male, 3 female; age range: 7-42 years; mean age: 25 years) diagnosed and treated at our institute. MR studies were performed on 3 T and 1.5-T clinical MR systems. All patients were reviewed by two experienced neuroradiologists and imaging findings were tabulated.
  
  
  RESULTS
  Five tumours were located in the posterior fossa, and two were in the pineal region. One of the tumours demonstrated multiple satellite lesions, which involved the midbrain, pons, medulla as well as the cervical cord. Tumours located in the pineal region compressed the 3rd ventricle/aqueduct and extended below the tentorium cerebelli. All the tumours demonstrated enhancement, and susceptibility was evident in six of the seven patients. CSF dissemination was present in two patients.
  
  
  CONCLUSIONS
  RGNTs are usually solid-cystic tumours and frequently demonstrate peripheral/heterogeneous enhancement upon post-contrast study. Haemorrhage is a common feature which may not be evident on CT. Cerebrospinal fluid (CSF) dissemination is a feature and appropriate imaging should be performed whenever an RGNT is suspected.
  
  
  CONCLUSIONS
  CT and MRI findings of seven RGNT cases were retrospectively reviewed. RGNTs are predominantly posterior fossa tumours. RGNTs are typically T1 hypointense and T2 hyperintense. Haemorrhage and peripheral/heterogeneous enhancement are common features of RGNTs. CSF dissemination is a feature of RGNTs and requires appropriate imaging.
authors.affiliation: Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, 560029, India.
authors.forename: Gorky
authors.initials: G
authors.lastname: Medhi
authors.affiliation: Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, 560029, India. chandrajitt2@gmail.com.
authors.forename: Chandrajit
authors.initials: C
authors.lastname: Prasad
authors.affiliation: Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, 560029, India.
authors.forename: Jitender
authors.initials: J
authors.lastname: Saini
authors.affiliation: Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, 560029, India.
authors.forename: Hima
authors.initials: H
authors.lastname: Pendharkar
authors.affiliation: Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, 560029, India.
authors.forename: Maya Dattatraya
authors.initials: MD
authors.lastname: Bhat
authors.affiliation: Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, India.
authors.forename: Paritosh
authors.initials: P
authors.lastname: Pandey
authors.affiliation: Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore, India.
authors.forename: Yasha
authors.initials: Y
authors.lastname: Muthane
mesh_terms: D000293:Adolescent; D000328:Adult; D002551:Cerebral Ventricle Neoplasms / Q000175:diagnosis*; D002648:Child; D005260:Female; D020546:Fourth Ventricle / Q000000981:diagnostic imaging / Q000473:pathology; D018303:Ganglioglioma / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D013116:Spinal Cord / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: CSF dissemination; Haemorrhage; Histopathology; Imaging; Rosette forming glioneuronal tumour