Gestational choriocarcinoma is a form of gestational trophoblastic neoplasia, which is a type of gestational trophoblastic disease (GTD), that can occur during pregnancy. It is a rare disease where the trophoblast, a layer of cells surrounding the blastocyst, undergoes abnormal developments, leading to trophoblastic tumors. The choriocarcinoma can metastasize to other organs, including the lungs, kidney, and liver. The amount and degree of choriocarcinoma spread to other parts of the body can vary greatly from person to person.Gestational choriocarcinoma can happen during and after any type of pregnancy event, though risk of the disease is higher in and after complete or partial molar pregnancies. Risk of disease may also be higher in those experiencing pregnancy at younger or older ages that average, such as below 15 years old or above 45 years old. Those with gestational choriocarcinoma may experience abnormal vaginal bleeding, abdominal pain, and have high levels of human chorionic gonadotropin (hCG), in addition to history of molar pregnancy or other metastatic cancer. A combination of history, symptoms, human chorionic gonadotropin levels, and imaging can be used in the diagnosis process, with ultrasonography being commonly used to image.
Causes
Gestational choriocarcinoma (GC) is the most aggressive form of trophoblastic tumor; it most commonly arises from certain fertilization defects, such as molar pregnancy, which results in increased level of growth factors and uncontrolled proliferation of trophoblasts in the uterus. Statistics from clinical cases have shown that GC is associated with any pregnancy events, with 50% of GC arise from hydatidiform moles, 25% from gestation, and 25% from abortion or tubal pregnancy. Risk factors
The exact underlying causes for this disease are still not fully elucidated, part of the reasons being that this condition is very rare and it is clinically hard to distinguish it from invasive mole, which are other type of trophoblastic tumor  that present some similarities as GC. But several risk factors have been reported to have association with gestational choriocarcinoma. Maternal age. This is one of the two well-established risk factors for GC. Many studies have shown that the risk of developing GC increased very rapidly in gestational women older than 40 years old. Prior history of complete hydatidiform mole. This is another well-established risk factor for GC. It has been showed that the risk of having GC after a complete hydatidiform mole is significantly higher than after a live birth. Others risk factors such as reproductive factors, use of oral contraceptives, diet and environmental factors were also reported. But because of data inconsistency, such associations are still questionable. For example, there is a case-control study showed that theres a significant association of GC in women having more than 5 births.