Complete hydatidiform moles account for 50% of all cases of choriocarcinoma. The same is true of choriocarcinoma arising in the ovary. The treatment for invasive mole or choriocarcinoma generally is the same. Choriocarcinoma tumor cells are TGF-B signaling resistant, as well as lacking Smad3 expression. Primary ovarian choriocarcinoma has a poor prognosis and can occur without a pregnancy. Elements of choriocarcinoma in a mixed testicular tumor have no prognostic importance. There are four main types of OGCTs, namely dysgerminomas, yolk sac tumor, teratoma, and choriocarcinoma. In infants and young children, these elements usually are endodermal sinus tumor, followed by choriocarcinoma. Li began to treat his choriocarcinoma patients with an antifolate chemotherapy drug called methotrexate. Ovarian hyperstimulation occurs more often with invasive moles and choriocarcinoma than complete molar pregnancies. Testicular choriocarcinoma has the worst prognosis of all germ-cell cancers. Choriocarcinoma arising in the testicle is rare, malignant and highly resistant to chemotherapy. Choriocarcinoma of the testicles has the worst prognosis of all germ-cell cancers. Choriocarcinoma is a malignant, trophoblastic cancer, usually of the placenta. Choriocarcinoma are trophoblastic tumors that form in the uterus from villous cells.