Hydatidiform mole (HM) or molar pregnancy is the most common form of GTD. It is most often benign (non-cancerous) and stays in the uterus. There are two types of HM: complete HM, which has a 15 to 25 percent chance of becoming cancer, and partial HM, which has a less than 5 percent chance of becoming cancer.

There are four main types of GTN:

• Invasive moles (chorioadenoma destruens): Cancerous growths that can develop from HM but rarely spread outside of the uterus.
• Choriocarcinoma: A tumor that can develop from HM or after an abortion, miscarriage, ectopic pregnancy, or full-term pregnancy. Choriocarcinomas are the most aggressive form of GTN and can spread throughout the pelvis and to distant sites, such as the lungs, brain, liver, and kidneys.
• Placental-site trophoblastic tumor (PSTT): A very rare, slow-growing cancer that develops from the placenta.
• Epithelioid trophoblastic tumor (ETT): A very rare cancer that is similar to choriocarcinoma but less aggressive.

Our gynecologic cancer specialists work with Penn Fertility Care specialists to create customized gestational trophoblastic disease (GTD) treatment plans that can help you build a family after treatment. This is often called a “fertility sparing approach” or “medical management” of cancer and other diseases that can affect the reproductive organs.

We have more full-time, board-certified gynecologic oncologists than any other hospital in the Philadelphia region. Our entire team, including medical oncologists, pathologists, surgeons and radiation specialists, meets weekly to discuss joint treatment plans for each of our unique patients. However, GTD and its treatment can affect the whole body. That’s why we partner closely with specialists throughout the Penn system: This collaborative model lets us take on a greater complexity of care.

GTD growths can be cancerous (malignant) or non-cancerous (benign). Most types of GTD are benign. However, some GTDs that start out benign can become malignant. Certain conditions can raise this risk.

GTD is very rare. In the United States, about 110 per 100,000 pregnancies develop into GTD.

Choriocarcinoma is very rare, affecting about 1 in 40,000 pregnancies. However, on average, one in 40 molar pregnancies will develop into choriocarcinoma.

If you have GTD, you will not be able to feel the tumor itself. However, you may feel pain or pressure in the abdomen or your uterus may become enlarged.

Most forms of GTD are benign (non-cancerous). However, cancerous forms, such as choriocarcinoma, can spread to other parts of the body if they are untreated.