Adult Apical Ligament of the Dens Lacks Notochordal Tissue: Application to Better Understanding the Origins of Skull Base Chordomas.
BACKGROUND
The apical ligament has long been reported to contain notochord remnants and thus might serve as a site of origin of chordoma formation at the skull base. However, to our knowledge, the histologic study of the apical ligament using histologic staining specific for notochordal tissue has not been previously performed. Therefore the current study was undertaken.


METHODS
Fifteen apical ligament samples underwent histologic examination with specific markers for notochordal differentiation.


RESULTS
Across all samples, there was no indication of any notochordal remnants.


CONCLUSIONS
On the basis of our cadaveric study, the apical ligament does not contain notochord tissue and in adults should not be considered a remnant of this structure. Moreover, it is unlikely that the apical ligament gives rise to chordomas at the craniocervical junction under normal circumstances.
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA; Seattle Science Foundation, Seattle, Washington, USA; Department of Trauma Surgery, BG University Hospital Bergmannsheil, Ruhr University Bochum, Germany. Electronic address: christian.fisahn@swedish.org.
Christian
C
Fisahn
Seattle Science Foundation, Seattle, Washington, USA.
Cameron
C
Schmidt
CellNetix Pathology, Seattle, Washington, USA.
Steven
S
Rostad
Department of Pathology, Children's of Alabama, Birmingham, Alabama, USA.
Rong
R
Li
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA.
Tarush
T
Rustagi
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA.
Fernando
F
Alonso
Tabriz University of Medical Sciences, Tabriz, Iran.
Mohammadali M
MM
Shoja
Seattle Science Foundation, Seattle, Washington, USA.
Joe
J
Iwanaga
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA.
Jens R
JR
Chapman
Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA.
Rod J
RJ
Oskouian
Seattle Science Foundation, Seattle, Washington, USA.
R Shane
RS
Tubbs
D000368:Aged; D000369:Aged, 80 and over; D002817:Chordoma / Q000473:pathology*; D005260:Female; D006801:Humans; D008022:Ligaments / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009672:Notochord / Q000473:pathology*; D019292:Skull Base Neoplasms / Q000473:pathology*
Anatomy; Apical ligament; Dens; Notochord; Spine chordoma