Published: Aug. 22, 2011
Updated: Aug. 22, 2011
Gestational trophoblastic disease (GTD) is a group of several diseases that involve abnormal cell growth in placental tissue in the uterus.
There are four types of gestational trophoblastic diseases:
Hydatidiform mole is the most common GTD and is usually not cancerous. Hydatidiform moles are also called molar pregnancies.
Hydatiform moles can be complete or partial. Complete hydatidiform moles develop because sperm fertilizes an empty egg. Partial hydatidiform moles develop when two sperm fertilize a normal egg. Though there is some fetal tissue involved, no viable fetus is being formed.
Hydatiform moles are often treated surgically. Some patients with complete hydatidiform moles may also require chemotherapy.
An invasive mole is a hydatidiform mole that invades the muscular wall of the uterus. If these moles grow through the myometrium, they can cause a hole in the uterus. Most invasive moles are treated with chemotherapy.
Persistent GTD refers to GTD that is not cured by local surgery. Persistent GTD is often caused because the surgery did not remove an invasive mole.
Choriocarcinoma often develops from a complete hydatidiform mole or after a normal pregnancy or one where the fetus was lost early on. Choriocarcinoma is malignant (cancerous) and more likely to spread to other organs. On rare occasions choriocarcinomas can develop in other parts of the body.
Placental-site trophoblastic tumor (PSTT) occurs when the placenta attaches abnormally to the uterus. These rare tumors most often develop after normal pregnancies or abortions. PSTTs do not often spread to other parts of the body and are treated surgically.
Learn more about gynecologic cancer: