绒毛膜癌比葡萄胎少见，如图所示。绒毛不存在，明显异型性的胚胎滋养层细胞增殖显著。具有很强的侵袭性，并与HCG关系密切。一半的绒毛膜癌发生于葡萄胎后。
Much less common than hydatidiform mole is choriocarcinoma, seen here. Villi are not present. Rather, there is a proliferation of bizarre trophoblastic cells. These tumors are very aggressive and are associated with very marked HCG levels. Half of choriocarcinomas arise in preceding hydatidiform moles.