title: Histological study of chordoma origin from fetal notochordal cell rests.
abstract: METHODS
  The histological comparative study was performed on chordoma and notochordal cell rests (NCRs).
  
  
  OBJECTIVE
  To understand the histological similarity and homology of chordoma and NCRs, further supplying direct evidence of chordoma origin from NCRs.
  
  
  BACKGROUND
  Although many studies supported the hypothesis that chordoma arise from NCRs, there has been little direct evidence reported to date. Of the base of our previous study, we conducted a comparative histological study among NCRs coexisting in chordoma, fetal NCRs, and chordoma tumor components.
  
  
  METHODS
  Thirty fetal nucleus pulposus and 46 chordoma specimens were harvested, and classic chordoma tumor markers and brachyury expression levels were investigated through immunohistochemical method.
  
  
  RESULTS
  The fetal NCRs existed in the form of clusters in the center of nucleus pulposus <36 gestational weeks; NCRs coexisting in chordoma specimens consisted of packed cells without extracellular myxoid matrix. Both the above-mentioned NCRs as well as chordoma tumor components showed high sensitivity for classic chordoma tumor makers (epithelial membrane antigen, AE1/AE3, CAM5.2, vimentin, S-100); both kinds of NCRs showed completely negative expression for brachyury, whereas chordoma tumor components demonstrated 100% positivity.
  
  
  CONCLUSIONS
  Our study results supported histological similarity and homology of NCRs coexisting in chordoma and in fetal nucleus pulposus. Brachyury activation probably takes an important role in chordoma tumoregenesis.
authors.affiliation: *Department of Orthopaedic Surgery, Suzhou Municipal Hospital, Affiliated Suzhou Hospital, Nanjing Medical University, Suzhou, Jiangsu Province, China; and †Department of Orthopaedic Surgery, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
authors.forename: Qin
authors.initials: Q
authors.lastname: Shi
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.forename: Dong-Lai
authors.initials: DL
authors.lastname: Wang
authors.forename: Tian-Ming
authors.initials: TM
authors.lastname: Zou
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Yang
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Zhu
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D002817:Chordoma / Q000378:metabolism / Q000473:pathology*; D005326:Fetal Proteins / Q000378:metabolism*; D005333:Fetus / Q000166:cytology; D006801:Humans; D009672:Notochord / Q000166:cytology* / Q000378:metabolism; D013125:Spinal Neoplasms / Q000378:metabolism / Q000473:pathology*; D020825:T-Box Domain Proteins / Q000378:metabolism*; D014746:Vimentin / Q000378:metabolism; D000098908:Brachyury Protein
chemical_list: D014408:Biomarkers, Tumor; D005326:Fetal Proteins; D020825:T-Box Domain Proteins; D014746:Vimentin; D000098908:Brachyury Protein