 |
MRI of
extensive clival chordoma in 17-year-old male patient, axial view. Tumor in the
nasopharynx extending from nasal cavity to brainstem posteriorly is clearly
visible. (Credit: wikipedia.org)
|
Chordoma is a rare slow-growing neoplasm thought
to arise from cellular remnants of the notochord.
The evidence for this is the location of the tumors (along the neuraxis), the
similar immunohistochemical staining patterns, and the demonstration that
notochordal cells are preferentially left behind in the clivus and sacrococcygeal regions when the
remainder of the notochord regresses during fetal life.
Chordomas can arise from bone in the skull base and anywhere
along the spine. The two most common locations are cranially at
the clivus and in the sacrum at the
bottom of the spine.
Genetics
A small number of families have been reported in which
multiple relatives have been affected by chordoma. In four of these families
duplication of the brachyury gene was found to be responsible for causing
chordoma.
A possible association with tuberous sclerosis complex(TSC1 or TSC2) has been
suggested.
 |
MRI of
extensive clival chordoma in 17-year old male patient, sagittal view. Tumor in
the nasopharynx extending from nasal cavity to brainstem posteriorly is clearly
visible. (Credit: wikipedia.org)
|
Epidemiology
In the United
States, the annual incidence of chordoma is
approximately 1 in one million (300 new patients each year).
There are currently no known environmental risk factors for
chordoma. As noted above germline duplication of brachyury has
been identified as a major susceptibility mechanism in several chordoma
families.
While most people with chordoma have no other family members
with the disease, rare occurrences of multiple cases within families have been
documented. This suggests that some people may be genetically predisposed to
develop chordoma. Because genetic or hereditary risk factors for chordoma may
exist, scientists at the National Cancer Institute are conducting a Familial
Chordoma Study to search for genes involved in the development of this tumor. Read more >>
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