title: Primary intradural chordoma: report on three cases and review of the literature.
abstract: OBJECTIVE
  Chordomas are rare malignant bone tumors of the skull base or sacrococcygeal region. They derive from notochordal remnants and usually have a chronic progressive course. Even rarer, intradural chordomas with a better biological behavior have also been reported. We present 3 further primary intradural extraosseous chordomas with a favorable clinical outcome.
  
  
  METHODS
  Two patients, a 38-year-old man and a 44-year-old woman, presented with neck pain. In these, intradural extraspinal tumors within intervertebral foramina were found. Both tumors were totally removed and the patients have been free of disease for 7 years and 1 year, respectively. The other patient, a 76-year-old man suffered from an unspecific gait disorder and diplopia as a result of a prepontine space-occupying lesion. In this case, only an incomplete tumor resection was possible but progression has not occurred for 5 years.
  
  
  METHODS
  Paraffin blocks from all cases were examined with classical histopathological stainings and immunohistochemistry for pancytokeratin, CK7, CK8/18, CK19, EMA, CEA, vimentin, S100, aktin, desmin, GFAP, CD117, PDGF-receptor alpha and beta, collagen-type-IV, p63, and Ki67. Fluorescent in situ hybridization was used to exclude EWS translocation.
  
  
  RESULTS
  All cases showed the typical histological picture with physaliphorous cells in a myxoid matrix and the characteristic immunohistochemical profile with positivity for vimentin, pancytokeratin, CK19, EMA, and S100. Staining for P63 and type IV collagen was consistently negative. Myxoid extraskeletal chondrosarcoma was excluded by in-situ-hybridization of the EWS gene.
  
  
  CONCLUSIONS
  Considering our cases in context with so far published literature, we conclude that intradural chordomas are rare and in this location usually have a better prognosis compared to classical intraosseous chordomas.
authors.affiliation: Department of Neuropathology, Klinikum Bremen-Mitte, Bremen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bergmann
authors.forename: Y
authors.initials: Y
authors.lastname: Abdalla
authors.forename: U
authors.initials: U
authors.lastname: Neubauer
authors.forename: H-U
authors.initials: HU
authors.lastname: Schildhaus
authors.forename: S
authors.initials: S
authors.lastname: Probst-Cousin
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002574:Cervical Vertebrae / Q000473:pathology*; D002817:Chordoma / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013120:Spinal Cord Neoplasms / Q000473:pathology* / Q000601:surgery