Early in a pregnancy, before there’s anything you can see with the naked eye, there’s a tiny group of cells -- an embryo -- in the uterus. Normally, cells on the inside of this group grow into a fetus. Cells on the outside turn into the placenta, which passes nutrients from mother to baby. Those outside cells are called trophoblast cells.
Gestational trophoblastic disease (GTD) is the name for a rare group of tumors made up of trophoblast cells. They form in the uterus and almost always are related to pregnancy. They can be cancer, but most of the time they’re not.
The most common kind of GTD occurs early in pregnancy, but some happen months or even years after you have a full-term baby. GTD can be treated, and most types -- even if they’re cancerous -- can be cured.
Types
Hydatidiform moles (HMs), are the most common GTD. At first, they can seem like a normal pregnancy. A basic test will show that you’re pregnant and you may even feel that way, but there’s no baby growing. There’s only a group of cysts (fluid-filled sacs). At around 6 to 10 weeks, your symptoms and routine tests will show that something’s not right.
HMs aren’t cancer, but they can sometimes lead to it. There are two types:
- Complete hydatidiform moles (CHMs) have no embryo or normal placental tissue.
- Partial hydatidiform moles (PHMs) may have some normal placental tissue, but the embryo rarely survives to term.
Invasive moles usually start as CHMs, but develop into cancer and grow into the muscle of the uterus. Very rarely, they start as PHMs instead. They may go away without treatment, but that’s not typical.
Choriocarcinoma is a rare cancer that often starts as an HM. It can also form from tissue that’s left in the uterus after an abortion, miscarriage, or delivery of a full-term baby. It’s an aggressive cancer that can spread throughout the body, including the uterus, lungs, and brain. It can also spread to a baby.
Placental-site trophoblastic tumors (PSTTs) and epithelioid trophoblastic tumors (ETTs) are both very rare. They can spread to the uterus and other parts of the body, but they might not be found for months or even years after a pregnancy.
Causes
Normally, when a sperm and egg join together, each one gives a set chromosomes to a new cell that starts to grow and divide. Chromosomes are bundles of genes that hold your DNA. For some reason, this process doesn’t go right with most types of GTD, but doctors aren’t sure why. The cause for GTD even when a full-term baby is delivered also isn’t clear.
You may be more likely to get a GTD if you:
- Get pregnant when you’re younger than 20 or older than 35
- Had a molar pregnancy in the past
Symptoms
Common signs and symptoms include:
- High blood pressure along with headaches and swelling in your hands and feet -- a condition known as preeclampsia
- Pain, pressure, or discomfort in your pelvis
- Shortness of breath, feeling very tired, and dizziness due to vaginal bleeding
- Showing sooner than expected because of a larger-than-normal uterus
- Throwing up and upset stomach that are much more intense than a normal pregnancy
- Vaginal bleeding not related to your menstrual cycle
GTD may also lead to an overactive thyroid, causing symptoms such as:
- Heartbeat that’s fast or not regular
- Shakiness
- Sweating
- Weight loss
Diagnosis
You find out you have GTD from the routine tests you get when you’re pregnant. Your doctor will ask about your symptoms and do a physical exam.
You may then get:
- Urine and blood tests to look for signs of tumors or other problems and to check your level of human chorionic gonadotropin (HCG) hormone (You normally have HCG when you’re pregnant, but it’s often higher when you have GTD.)
- Pelvic ultrasound, which can show if there’s a normal fetus or not
- Imaging, such as X-ray, CT scan, MRI, or PET scan to check if GTD has spread
Treatment
How your GTD is treated depends on what type it is, whether it has spread, and whether you may want to have children in the future. Most women are able to have a normal pregnancy after they’re treated for GTD.
Surgery is often the first step for tumors that haven’t spread. Dilation and curettage (D&C) is a common treatment where your doctor widens the cervix and scrapes the uterus with a tool called a curette. You can usually go home the same day.
If you don’t wish to have any more children, a hysterectomy -- surgery to remove your uterus -- is another option. This isn’t common with HMs, but it’s standard for PSTTs and ETTs to make sure all the cancer cells get removed.
Chemotherapymay be used if GTD spreads into the uterus or other parts of the body. It’s often done after surgery to help prevent cancer from coming back.
Radiation therapyuses high-energy beams from X-rays or other sources to kill cancer cells. It’s typically only used if GTD has spread and chemotherapy isn’t working well.
