The third subtype is a choriocarcinoma and it's made of germ cells that turn into syncytiotrophoblast cells which are the ones that help form the placenta.

第三种亚型是绒毛膜癌，它是由转化成合体滋养细胞的生殖细胞组成，合体滋养细胞帮助形成胎盘。