Skeletal Radiology

, Volume 36, Issue 1, pp 59–65

Diagnosing an extra-axial chordoma of the proximal tibia with the help of brachyury, a molecule required for notochordal differentiation

  • Paul O’Donnell
  • Roberto Tirabosco
  • Sonja Vujovic
  • William Bartlett
  • Timothy W. R. Briggs
  • Stephen Henderson
  • Chris Boshoff
  • Adrienne M. Flanagan
Case Report

DOI: 10.1007/s00256-006-0167-4

Cite this article as:
O’Donnell, P., Tirabosco, R., Vujovic, S. et al. Skeletal Radiol (2007) 36: 59. doi:10.1007/s00256-006-0167-4

Abstract

Chordomas are rare malignant bone tumours considered to arise from notochordal remnants that persist in the axial skeleton. Although their morphology can resemble that of a carcinoma, chondrosarcoma or malignant melanoma, the axial location and their well-defined immunophenotype, including expression of cytokeratins (CK7/20/8/18/19) and S100, generally allow the diagnosis to be made with confidence once the possibility is considered. In contrast, making a robust diagnosis of an extra-axial chordoma has been difficult in the absence of specific markers for chordomas. We have recently shown in gene expression microarray and immunohistochemistry studies that brachyury, a transcription factor crucial for notochordal development, is a specific and sensitive maker for chordomas. We now present a case of an intracortical tibial tumour, with detailed report of the imaging, and morphological features consistent with a chordoma, where notochordal differentiation was demonstrated with an antibody to brachyury. The tumour cells were also positive for cytokeratins, including CK19, and S100, CEA, EMA and HMBE1, findings which support the diagnosis of chordoma. Brachyury can be employed as a marker of notochordal differentiation and help identify confidently, for the first time, extra-axial bone and soft tissue chordomas, and tumours which may show focal notochordal differentiation.

Keywords

ChordomaParachordomaChordoma periphericumClear cell chondrosarcomaIntracorticalBone marrow oedemaBone tumourMRICT

Copyright information

© ISS 2006

Authors and Affiliations

  • Paul O’Donnell
    • 1
    • 5
  • Roberto Tirabosco
    • 2
  • Sonja Vujovic
    • 3
  • William Bartlett
    • 4
  • Timothy W. R. Briggs
    • 4
  • Stephen Henderson
    • 3
  • Chris Boshoff
    • 3
  • Adrienne M. Flanagan
    • 2
    • 5
  1. 1.Department of RadiologyRoyal National Orthopaedic HospitalStanmoreUK
  2. 2.Department of HistopathologyRoyal National Orthopaedic HospitalStanmoreUK
  3. 3.Wolfson Institute for Biomedical ResearchUniversity College LondonLondonUK
  4. 4.Department of Orthopaedic SurgeryRoyal National Orthopaedic HospitalStanmoreUK
  5. 5.Institute of Orthopaedics and Musculoskeletal ScienceUniversity College LondonStanmoreUK