View source for Chordoma

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{{Image|Chordoma.PNG|right|250px|[[MRI|MRI scan]] of a patient with a very pronounced chordoma (yellow circle) in the [[clivus|clival]] region (green circle).}} 
A '''chordoma''' (also known as choroid meningioma, chordocarcinoma, chordoepithelioma, or notochordoma) is a [[malignant tumor]] arising from the [[embryonic development|embryonic]] remains of the [[notochord]].<ref name=MeSH>{{MeSH}}</ref>

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==Etymology==
The term derives &mdash; in analogy of [[carcinoma]] &mdash; from the [[Latin (language)|Latin]] word ''chorda'' for [[string]] and the [[Greek (language)|Greek]] suffix ''-oma'' designating a [[swelling]].

==Etiology==
Chordomas are the result of abnormal tissue growth in remnants of the notochord. As such, they can occur anywhere in the bony tissue surrounding the [[spinal cord]], with [[cranial]], [[spine|spinal]] and [[sacral]] tumours each representing about one third of the cases.  The most common cranial location is in the clival region of the skull near the brainstem and the most common sacral lesion is in the body of the sacrum.<ref name="urlPrimary Malignant Bone Tumors: Tumors of Bones and Joints: Merck Manual Professional">{{cite web | url = http://www.merck.com/mmpe/sec04/ch044/ch044c.html#sec04-ch044-ch044c-1188 | title = Primary Malignant Bone Tumors: Tumors of Bones and Joints: Merck Manual Professional | author = | authorlink = | coauthors = | date = | format = | work = | publisher = | pages = | language = | archiveurl = | archivedate = | quote = | accessdate = 2010-05-14}}</ref>

==Demographics==
The [[prevalence]] is about 1 in a million in the United States, and affected patients have an average life expectancy of five to ten years after diagnosis, with differences according to age of onset, gender and ethnicity.<ref name=McMaster2001>{{CZ:Ref:McMaster 2001 Chordoma: incidence and survival patterns in the United States, 1973-1995}}</ref>

==Diagnostics==
Chordomas are most frequently identified on the basis of [[MRI|MRI scans]]. They can also, with lower probability, be identified on [[CT scan]]s, particularly if the tumour has grown considerably. [[Histology|Histologically]], chordomas can be identified using a variety of [[immunohistochemical]] markers.
{{Image|Chordoma immunohistochemistry.png|right|250px|Different [[immunohistochemical marker]]s of chordoma. A: [[Ethyl eosin]] staining of a chordoma composed of nests and cords of tumour cells; B: Ethyl eosin staining of [[physaliphorous cell]]s containing multiple clear [[cytoplasm]]ic [[vacuole]]s; C: [[immunohistochemistry]] showing staining for [[S-100 protein]]; D: immunohistochemistry showing staining for [[cytokeratin]]; E: immunohistochemistry showing staining for [[Epithelial membrane antigen|EMA]]; F: immunohistochemistry showing staining for [[Vimentin]]. Scale: Panel A is 6.4 mm wide, all others 1.6 mm.}}

==Genetics==
At least one [[susceptibility gene]] has been identified<ref name=Yang2009>{{CZ:Ref:Yang 2009 T (brachyury) gene duplication confers major susceptibility to familial chordoma}}</ref> 

==Therapy==

Some variants of [[chemotherapy]] &mdash; notably [[imatinib]]-based ones &mdash; can achieve [[partial response]] or [[static disease]] in some cases<ref>[http://www.chordomafoundation.org/treatment/treatments.aspx Treatments options] &mdash; a list compiled by the [[Chordoma Foundation]] on the basis of the peer-reviewed literature on the subject</ref>, and chordoma [[cell line]]s have been reported to be sensitive to several [[chemotherapeutic]]s<ref>{{CZ:Ref:Yang 2010 Characterization and Analysis of Human Chordoma Cell Lines}}</ref>. However, no cure is in sight. This leaves [[surgery]] as the main option of treatment<ref>{{CZ:Ref:Boriani 2006 Chordoma of the mobile spine: fifty years of experience}}</ref>, with prospects of success varying according to location.

==References==
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