title: Cytokeratin-positive meningeal peripheral PNET/Ewing's sarcoma of the cervical spinal cord: diagnostic value of genetic analysis.
abstract: Peripheral primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES) of the central nervous system is extremely rare and should be differentiated from central PNET and other small blue round cell tumors. We describe a case of a meningeal peripheral PNET/ES of the spinal cord in an 11-year-old boy. Immunohistochemically, the small blue round cell tumor showed expression of epithelial markers and of CD99, thus posing an important differential diagnostic problem with a poorly differentiated synovial sarcoma. Fluorescence in situ hybridization revealed rearrangement of the EWS gene, as seen in peripheral PNET/ES. Peripheral PNET/ES does occur in the central nervous system, but its diagnosis can be extremely difficult on morphologic and immunohistochemical grounds alone. Genetic analysis plays a key role in its distinction from other small blue round cell tumors.
authors.affiliation: Department of Pathology, University Hospital, Catholic University of Leuven, Leuven, Belgium.
authors.forename: Heidi
authors.initials: H
authors.lastname: Woestenborghs
authors.forename: Maria
authors.initials: M
authors.lastname: Debiec-Rychter
authors.forename: Marleen
authors.initials: M
authors.lastname: Renard
authors.forename: Philippe
authors.initials: P
authors.lastname: Demaerel
authors.forename: Frank
authors.initials: F
authors.lastname: Van Calenbergh
authors.forename: Stefaan
authors.initials: S
authors.lastname: Van Gool
authors.forename: Raf
authors.initials: R
authors.lastname: Sciot
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000378:metabolism; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D002648:Child; D003937:Diagnosis, Differential; D006801:Humans; D007633:Keratins / Q000378:metabolism*; D007796:Laminectomy; D008297:Male; D008578:Meninges / Q000473:pathology*; D018396:Mucin-1 / Q000378:metabolism; D018242:Neuroectodermal Tumors, Primitive / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D012512:Sarcoma, Ewing / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D013584:Sarcoma, Synovial / Q000175:diagnosis; D032681:Spectral Karyotyping; D013116:Spinal Cord / Q000601:surgery; D013120:Spinal Cord Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D014746:Vimentin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D018396:Mucin-1; D014746:Vimentin; D007633:Keratins