• Choriocarcinoma is a very rapidly growing malignancy that tends to spread quickly. About 50 percent of all
cases of gestational choriocarcinoma follow a hydatidiform mole, 25 percent follow a spontaneous abortion or
tubal pregnancy and 25 percent follow a normal pregnancy. Choriocarcinoma follows a normal-term pregnancy
in 1 in 40,000 pregnancies. GTD after a normal pregnancy is always a choriocarcinoma, never a mole or an
invasive mole.
What Causes It A complete hydatidiform or invasive mole occurs when a single sperm fertilizes an egg without a nucleus. The chromosomes in the sperm duplicate, resulting in an abnormal embryo that has only male genetic material. A mole can also occur when two sperm fertilize a single egg. A mole develops from the abnormally fertilized egg and is characterized by a lack of a normal fetus and by many small fluid-filled cysts.
The cause of choriocarcinoma is uncertain. It can arise from a normal pregnancy, a miscarriage, a tubal pregnancy or from either type of mole.
How It Spreads Hydatidiform moles generally stay confined to the endometrial cavity. When it begins to invade the wall of the uterus , it is called an invasive mole. Occasionally a hydatidiform mole and an invasive mole can spread to distant sites, most typically to the lung.
