title: Glioneuronal tumours with features of rosette-forming glioneuronal tumours of the fourth ventricle and dysembryoplastic neuroepithelial tumours: a report of three cases.
abstract: OBJECTIVE
  To study three atypical glioneuronal tumours (GNTs), in order to shed light on the clinical and pathological features of this diverse tumour group.
  
  
  RESULTS
  Clinical and neuropathological data for each case were retrospectively reviewed. Case 1 involved a 17-year-old boy with left leg movement difficulty. A mass lesion in the basal ganglia was detected radiologically; histopathological features included neurocytic/perivascular rosettes and a pilocytic astrocytoma component. Case 2 involved a 33-year-old man with intractable epilepsy. His left parietal lobe contained a cyst-like mass, resembling dysembryoplastic neuroepithelial tumour and rosette-forming glioneuronal tumour of the fourth ventricle microscopically. Case 3 involved a 21-year-old woman with a mass lesion in the mesencephalic tegmentum extending to the third and fourth ventricles and the suprasellar region. The lesion contained perivascular/neurocytic rosettes and an oligodendroglioma-like component. None of the tumours expressed an isocitrate dehydrogenase I mutation of the R132H type or contained a 1p/19q deletion, a BRAF(V600E) mutation, or KIAA1549-BRAF fusion.
  
  
  CONCLUSIONS
  We describe three GNTs with atypical histopathology and locations. Additional cases and molecular studies are needed to better understand the biological nature of GNTs and to refine their classification system.
authors.affiliation: Department of Neuropathology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Shi-Yun
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Neuropathology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Neuropathology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Lei-Ming
authors.initials: LM
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Qing-Tang
authors.initials: QT
authors.lastname: Lin
authors.affiliation: Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Guo-Guang
authors.initials: GG
authors.lastname: Zhao
authors.affiliation: Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Geng
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Neuropathology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: De-Hong
authors.initials: DH
authors.lastname: Lu
authors.affiliation: Department of Neuropathology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Yue-Shan
authors.initials: YS
authors.lastname: Piao
mesh_terms: D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000235:genetics / Q000473:pathology*; D001479:Basal Ganglia / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology*; D005260:Female; D020546:Fourth Ventricle / Q000473:pathology; D005910:Glioma / Q000235:genetics / Q000473:pathology*; D006801:Humans; D008297:Male; D018302:Neoplasms, Neuroepithelial / Q000235:genetics / Q000473:pathology*; D010296:Parietal Lobe / Q000473:pathology; D012189:Retrospective Studies; D012397:Rosette Formation; D055815:Young Adult
keywords: dysembryoplastic neuroepithelial tumours; glioneuronal tumours; molecular analysis; rosette-forming glioneuronal tumours