title: Extraventricular neurocytoma with atypical features and ganglionic differentiation.
abstract: Extraventricular neurocytoma (EVN) is an unusual variant of central neurocytoma located outside the ventricular system. Both tumours share a similar histology characterised by monotonous populations of round-to-oval cells with scanty cytoplasm separated by neuropil and branching capillaries. We report an EVN arising from the right frontal lobe near the olfactory tract in a 34-year-old male with worsening chronic epilepsy. Our patient's tumour exhibited many uncommon features including ganglionic differentiation, increased mitotic activity and a high proliferative index. We discuss the important differential diagnoses given the site of the tumour as well as the differentiating features from olfactory neuroblastoma, oligodendroglioma, anaplastic ganglioglioma and supra-tentorial primitive neuroectodermal tumour.
authors.affiliation: Department of Tissue Pathology, ICPMR, Westmead Hospital, Westmead, New South Wales, Australia. shaunchou@yahoo.com.au
authors.forename: Shaun
authors.initials: S
authors.lastname: Chou
authors.forename: Winny
authors.initials: W
authors.lastname: Varikatt
authors.forename: Mark
authors.initials: M
authors.lastname: Dexter
authors.forename: Thomas
authors.initials: T
authors.lastname: Ng
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000502:physiology; D005625:Frontal Lobe / Q000473:pathology*; D005724:Ganglia / Q000473:pathology*; D006801:Humans; D008297:Male; D018306:Neurocytoma / Q000473:pathology*; D009833:Olfactory Pathways / Q000473:pathology*