Tumor derived from persistent notochord within the sacrum and skull base, typically:
Sacrum most commonly (~45%)
Clivus slightly less commonly (~35%)
Vertebral column least commonly, (~ 20%).
The mean age of presentation is 60 y.o. and the prognosis is poor (typical survival < 10 years)
Although the intervertebral disks contain vestigial notochord (within the nucleus pulposus), chordomas derive from the vertebral bodies: the bony portion of the spine, rather than the jelly-like disk.
Chordomas are soft, slimy, glistening, lobulated masses with mixed fluid/gelatinous mucoid material.
Their appearance helps us associate them with the jelly-like substance of the intervertebral disks (but remember they grow out of the vertebral bodies).
Chordomas are infiltrative, thus they destroy the bony portion of the spine and invade surrounding neural spaces.
Microscopically, they notably contain physaliphorous cells (vacuolated cells).
Subtypes:
Conventional chordoma
Chondroid chordoma
Dedifferentiated chordoma (rapidly fatal)
References
“Chordoma - Conditions - Neurooncology - Specialties - UR Neurosurgery - University of Rochester Medical Center.” Accessed July 22, 2018. https://www.urmc.rochester.edu/neurosurgery/specialties/neurooncology/conditions/chordoma.aspx.
Folpe, Andrew L., and Carrie Y. Inwards. Bone and Soft Tissue Pathology E-Book: A Volume in the Foundations in Diagnostic Pathology Series. Elsevier Health Sciences, 2009.
IV, Griffith R. Harsh, and Francisco Vaz-Guimaraes. Chordomas and Chondrosarcomas of the Skull Base and Spine. Academic Press, 2017.
Nikoghosyan, Anna V, Irini Karapanagiotou-Schenkel, Marc W Münter, Alexandra D Jensen, Stephanie E Combs, and Jürgen Debus. “Randomised Trial of Proton vs. Carbon Ion Radiation Therapy in Patients with Chordoma of the Skull Base, Clinical Phase III Study HIT-1-Study.” BMC Cancer 10 (November 5, 2010): 607. https://doi.org/10.1186/1471-2407-10-607.
Shapiro, Irving M., and Makarand V. Risbud. “Transcriptional Profiling of the Nucleus Pulposus: Say Yes to Notochord.” Arthritis Research & Therapy 12 (May 20, 2010): 117. https://doi.org/10.1186/ar3003.