title: Primary peripheral PNET/Ewing's sarcoma of the dura: a clinicopathologic entity distinct from central PNET.
abstract: We describe two cases of peripheral primitive neuroectodermal tumor-Ewing's sarcoma (PNET-ES) arising intracranially in the leptomeninges. Both tumors exhibited a primitive undifferentiated round-cell morphology. Immunohistochemical stains revealed strong membrane expression of CD99 in both cases. A t(11;22)(q24;q12) could be demonstrated with reverse transcriptase-polymerase chain reaction in one case, whereas fluorescence in situ hybridization analysis performed in the second case showed a rearrangement of the EWS gene. The occurrence of PNET-ES at this site is very unusual. Immunophenotypical as well as genetic analysis play a key role in the diagnosis and the distinction from central PNET.
authors.affiliation: Department of Pathology, Katholieke Universiteit Leuven, Belgium.
authors.forename: Franceska
authors.initials: F
authors.lastname: Dedeurwaerdere
authors.forename: Caterina
authors.initials: C
authors.lastname: Giannini
authors.forename: Raf
authors.initials: R
authors.lastname: Sciot
authors.forename: Brian P
authors.initials: BP
authors.lastname: Rubin
authors.forename: Giorgio
authors.initials: G
authors.lastname: Perilongo
authors.forename: Laura
authors.initials: L
authors.lastname: Borghi
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Ballotta
authors.forename: Erwin
authors.initials: E
authors.lastname: Cornips
authors.forename: Anouk
authors.initials: A
authors.lastname: Demunter
authors.forename: Brigitte
authors.initials: B
authors.lastname: Maes
authors.forename: Angelo P
authors.initials: AP
authors.lastname: Dei Tos
mesh_terms: D000071443:12E7 Antigen; D015703:Antigens, CD / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D002648:Child; D002869:Chromosome Aberrations; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D003937:Diagnosis, Differential; D004388:Dura Mater / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008577:Meningeal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016900:Neurofilament Proteins / Q000032:analysis; D009418:S100 Proteins / Q000032:analysis; D012512:Sarcoma, Ewing / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016708:Synaptophysin / Q000032:analysis
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D016900:Neurofilament Proteins; D009418:S100 Proteins; D016708:Synaptophysin