The fourth subtype is a dysgerminoma and it's made of germ cells that turn into oocytes, which is the normal pattern, but then they start to grow uncontrollably.

第四种亚型无性瘤，它由转化为卵母的生殖成，虽然这正常发育，之后它们开始增长失控。

The four major types of germ cell tumors are: fetal teratomas, both mature cystic and immature teratomas; yolk sac tumors, or endodermal sinus tumor, choriocarcinoma or placental tissue tumors and finally dysgerminomas or oocyte tumors.

4种卵巢癌如下：畸胎瘤，包括成熟囊性畸胎瘤和未成熟畸胎瘤；卵黄囊瘤，又叫内胚窦瘤；绒毛膜癌，又叫胎盘织肿瘤；最后无性瘤，又叫卵母瘤。