Gestational choriocarcinoma is a condition due to abnormal growth from placental tissue. It is often grouped under gestational trophoblastic neoplasia (GTN) and is the most aggressive form of GTN, with common metastases to the lungs, vagina, liver, and brain and is associated with elevated levels of human chorionic gonadotropin. These malignancies arise with components of both syncytiotrophoblasts and cytotrophoblasts but without chorionic villi.

Approximately 25% of initial identifications will be associated with a molar pregnancy. It is more common after having a complete, versus partial, mole. About 50% of cases will follow full-term pregnancies. Risk factors include increased age at time of pregnancy and history of a prior molar pregnancy. Incidence is approximately 1 in 40 000 pregnancies in North America and Europe.

Most cases are identified by an abnormally trending beta-human chorionic gonadotrophin (bhCG) curve following evacuation of a molar pregnancy or by the patient having abnormal postpartum bleeding. In some cases, pathologic evaluation of evacuated molar pregnancy tissue or postdelivery placenta will identify choriocarcinoma.