Editing Germ cell tumor (section)

==Location==

GCTs most commonly arise in the [[testis]], followed by the [[ovary]] and extragonadal sites. Extragonadal GCTs tend to arise in the midline, most commonly at the following sites:<ref>{{cite web | url=https://www.cancer.gov/types/extragonadal-germ-cell/patient/extragonadal-treatment-pdq | title=Extragonadal Germ Cell Tumors Treatment - NCI | date=22 November 2004 }}</ref>
* [[Human cranium|Central nervous system]] — in the [[pineal]] gland or [[sella turcica]]
* Head and neck — inside the [[mouth]]
* [[mediastinal germ cell tumor|Mediastinum]]
* [[Retroperitoneum]]
* [[Spinal column|Spine]], particularly [[sacrococcygeal teratoma]]

In females, GCTs account for 20-25% of ovarian tumors, but are predominantly benign mature teratomas. Malignant ovarian GCTs are comparatively rare, and consist of immature teratomas, dysgerminomas, yolk sac tumors, and mixed germ cell tumors.<ref>{{cite journal | pmc=10093990 | date=2023 | last1=Cong | first1=L. | last2=Wang | first2=S. | last3=Yeung | first3=S. Y. | last4=Lee | first4=J. H. | last5=Chung | first5=J. P. | last6=Chan | first6=D. Y. | title=Mature Cystic Teratoma: An Integrated Review | journal=International Journal of Molecular Sciences | volume=24 | issue=7 | page=6141 | doi=10.3390/ijms24076141 | doi-access=free | pmid=37047114 }}</ref><ref>{{cite web | url=https://www.uptodate.com/contents/ovarian-germ-cell-tumors-pathology-epidemiology-clinical-manifestations-and-diagnosis | title=UpToDate }}</ref>

In males, GCTs account of 95% of [[testicular cancer|testicular tumors]], and are all considered malignant. [[Seminoma]] is the most common diagnosis (50%), followed by mixed-germ cell tumor (40%), and other pure GCTs.<ref>{{cite web | url=https://tumourclassification.iarc.who.int/chaptercontent/36/113 | title=BlueBooksOnline }}</ref> In [[neonates]], [[infants]], and [[children]] younger than 4 years, most are [[sacrococcygeal teratoma]]s.{{cn|date=May 2021}}

Males with [[Klinefelter syndrome]] have a 50 times greater risk of GSTs.<ref name=pmid9725401>{{cite journal | vauthors = Bebb GG, Grannis FW, Paz IB, Slovak ML, Chilcote R | title = Mediastinal germ cell tumor in a child with precocious puberty and Klinefelter syndrome | journal = The Annals of Thoracic Surgery | volume = 66 | issue = 2 | pages = 547–548 | date = August 1998 | pmid = 9725401 | doi = 10.1016/S0003-4975(98)00504-9 }}</ref>  In these persons, GSTs usually contain nonseminomatous elements, present at an earlier age, and seldom are gonadal in location.{{Medical citation needed|date=November 2017}}