[citation needed] Some investigators suggest that this distribution arises as a consequence of abnormal migration of germ cells during embryogenesis.

In younger women, they are more common, thus in patients under the age of 21, 60% of ovarian tumors are of the germ-cell type, and up to one-third are malignant.

[medical citation needed] Women with benign GCTs such as mature teratomas (dermoid cysts) are cured by ovarian cystectomy or oophorectomy.

[14] If the patient is in her reproductive years, an alternative is unilateral salpingoophorectomy, while the uterus, the ovary, and the fallopian tube on the opposite side can be left behind.

[15] The chemotherapy regimen most commonly used in GCTs is called PEB (or BEP), and consists of bleomycin, etoposide, and a platinum-based antineoplastic (cisplatin).

[13] Targeted treatments, such as immunotherapy, hormonal therapy and kinase inhibitors, are being evaluated for tumors that do not respond to chemotherapy.

[16] The 1997 International Germ Cell Consensus Classification[17] is a tool for estimating the risk of relapse after treatment of malignant germ-cell tumor.

A 1993 study of outcomes in Scotland found that for 454 men with nonseminomatous (nongerminomatous) GCTs diagnosed between 1975 and 1989, five-year survival increased over time and with earlier diagnosis.