Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD) refers to tumor types that arise from the placenta. GTD occurs in about 1 in every 1,000 pregnancies in the United States.

All GTD tumors grow from a type of cell in the placenta called a trophoblast. With GTD, the trophoblasts grow abnormally.

GTD tumors are considered either precancerous or cancerous. Because all GTD tumors have some risk of becoming cancer, it’s best to see a GTD specialist for care if you’re diagnosed with one.

With expert support, most women are cured of GTD and often can have future pregnancies.

Types of GTD

Healthcare providers group the types of gestational trophoblastic diseases into two categories:

• Precancerous conditions: Complete or partial hydatidiform mole (molar pregnancy) and atypical placental site nodules
• Cancer: Gestational trophoblastic neoplasia

Molar pregnancy

A hydatidiform mole (molar pregnancy) is the most common form of GTD. This occurs when a fertilized egg has an extra set of chromosomes from the sperm.

A partial mole has three sets of chromosomes (one from the mother and two from the father). There’s a fetus, but it can’t develop normally. Healthcare providers often misdiagnose partial moles as a regular miscarriage at first. Once a pathologist examines the tissue, they can diagnose it as a partial mole.

A complete mole has two sets of chromosomes, but all of them come from the father. This results in a condition with only placental cells and no fetus. It presents as grape-like cysts that fill your uterus. Providers usually diagnose it with an ultrasound.

Most molar pregnancies aren’t cancerous. But they have the potential to become cancerous without proper treatment. Up to 5% of partial moles and 25% of complete moles will become cancerous. They can be life-threatening unless they’re properly diagnosed and treated.

Atypical placental site nodule

An atypical placental site nodule occurs following a normal pregnancy or miscarriage. It often causes persistent vaginal bleeding months after the pregnancy has ended.

An atypical placental site nodule can only be diagnosed after a uterine biopsy, when a pathologist looks at the tissue under a microscope.

It’s not cancer, but about 15% of women diagnosed with an atypical placental site nodule will later develop a rare type of trophoblastic disease known as an epithelioid trophoblastic tumor (ETT).

Because ETT is very aggressive, your provider will likely recommend a hysterectomy if you have an atypical placental site nodule and don’t want a future pregnancy. You’ll have close monitoring if you do want a future pregnancy.

Gestational trophoblastic neoplasia (GTN)

GTNs are cancerous placental tumors. Types include:

• Invasive mole: The tumor grows into your uterine muscle. The cancer cells may stay there. But they can spread to any other area of your body, including your vagina, lungs, liver or brain.
• Choriocarcinoma: This cancer grows and spreads quickly. Choriocarcinoma usually follows a normal pregnancy, ectopic pregnancy or miscarriage. This may be found in the placental tissue at the time of delivery or later if you have long-term vaginal bleeding. Choriocarcinoma can also occur years after the last pregnancy, in any part of your body.
• Placental site trophoblastic tumor (PSTT): This is a less common tumor that usually presents as a uterine mass. Symptoms, like abnormal vaginal bleeding, may appear years after pregnancy.
• Epithelioid trophoblastic tumor (ETT): This is the rarest type of GTD tumor. It usually presents as a nodule within the muscle part of the uterus. Abnormal vaginal bleeding is a common first symptom.

Symptoms of gestational trophoblastic disease

Symptoms of gestational trophoblastic disease can include:

• Irregular vaginal bleeding or bleeding that’s unrelated to your period
• Pain in your abdomen or pelvis
• Severe nausea and vomiting in pregnancy
• A mass in your pelvis or uterus
• High blood pressure or swollen hands and feet early in pregnancy
• Prolonged vaginal bleeding after childbirth or miscarriage

Contact your healthcare provider if you have any of these symptoms. Some people have no symptoms of GTD. Others have symptoms that mimic pregnancy.

A uterus that seems to be growing much more quickly than in a normal pregnancy can be a sign of GTD. But you might not be able to tell that your uterus is unusually big.

GTD causes

GTD happens because of imbalances in the amount of genetic material that comes from the egg and the sperm after fertilization.

This leads to abnormal trophoblast (placenta) cell growth. Trophoblast cells grow from a fertilized egg and normally support a growing fetus. In GTD, the trophoblast cells grow without receiving the normal instructions on growth from the fetus.

GTD can occur after any pregnancy event, including:

• Miscarriage or abortion
• Tubal (ectopic) pregnancy
• Typical pregnancy

You can’t prevent gestational trophoblastic disease.

Risk factors

GTD is rare. But certain factors beyond your control may increase your risk, including:

• Being older than 40 or younger than 20 when you’re pregnant
• Having prior molar pregnancies

Complications of this condition

GTDs can cause a range of complications, depending on the type. Some complications include:

• Overactive thyroid and thyroid storm
• Excessive vaginal bleeding
• Anemia
• Preeclampsia
• Severe problems with breathing

How doctors diagnose this condition

Diagnosing GTD may involve:

• A pelvic exam
• An ultrasound
• Blood tests, especially human chorionic gonadotropin (hCG) hormone levels
• A biopsy

Your healthcare provider will also find the type of GTD. If it’s a cancerous type, they’ll suggest more tests to see if the cancer cells have spread. Imaging tests may include a CT scan, MRI and/or chest X-ray.

Your provider will assign a stage to the tumor if it’s cancerous. In cases of invasive mole or choriocarcinoma, they’ll also give it a risk score (like low- or high-risk). These details help guide treatment.

How is it treated?

Gestational trophoblastic disease treatment varies depending on several factors, like:

• GTD type, size and location
• The tumor’s staging and risk score
• Whether GTD occurred after a molar pregnancy, miscarriage or typical pregnancy
• Your overall health
• Your medical history and previous treatment for GTD
• Your plans for biological children

Together, you and your healthcare provider will agree on a treatment plan that works best for you.

Surgery is often necessary for any type of GTD. Your provider will remove the mole or tumor from your uterus. The most common surgery for GTD is a dilation and curettage (D&C).

Other treatments may include:

• Chemotherapy
• Radiation
• Hysterectomy

After treatment, your provider will want to check your hCG levels over time. This helps them know if the tumor is completely gone.

What can I expect if I have this condition?

Overall, the outlook (prognosis) for GTD is very good. Proper treatment most often cures GTD. Your healthcare provider can give you a better idea of what to expect based on your specific situation.

Most people with a history of GTD can expect to have typical pregnancies afterward. But you may need extra tests and monitoring for subsequent pregnancies.