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.

第四种亚型是无性细胞瘤，它是由转化为卵母细胞的生殖细胞组成，虽然这是正常发育模式，但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种卵巢细胞癌如下：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，又叫胎盘组织肿瘤；最后是无性细胞瘤，又叫卵母细胞瘤。