Cancerous gestational trophoblastic disease

A cancerous (malignant) tumour can grow into nearby tissue and destroy it. The cancer cells can also spread (metastasize) to other parts of the body.

Gestational trophoblastic disease (GTD) is usually non-cancerous (benign). But in rare cases abnormal trophoblastic cells can form a cancerous tumour or a non-cancerous hydatidiform mole can become cancerous. Cancerous GTD is also called gestational trophoblastic neoplasia (GTN).

An invasive mole is a cancerous tumour made up of abnormal trophoblast cells that have grown into the muscle wall of the uterus (called the myometrium).

This type of cancerous GTD can sometimes develop from a hydatidiform mole. Invasive moles can also develop if abnormal trophoblast cells are left behind after surgery to remove a hydatidiform mole. An invasive mole that develops after a hydatidiform mole is removed may be called a persistent mole or persistent trophoblastic disease.

Invasive moles usually need to be treated, but sometimes they go away on their own. Although invasive moles are cancerous, they rarely spread out outside of the uterus. Even if an invasive mole spreads, it can often be successfully treated.

Gestational choriocarcinoma is a rare cancerous type of GTD. It can develop from trophoblast tissue left in the uterus after a miscarriage, an abortion, or a normal pregnancy.

In rare cases, a choriocarcinoma can develop from germ cells (egg cells in the ovary or sperm cells in the testicle) rather than trophoblast cells. These are types of germ cell tumours called non-gestational choriocarcinomas. Find out more about cancerous tumours of the ovary and cancerous tumours of the testicle.

A gestational choriocarcinoma can grow into the muscle wall of the uterus and nearby blood vessels. It can also spread to other parts of the body, such as the lungs, vagina, brain or liver. In rare cases, it can spread to the skin, gastrointestinal (GI) tract, kidneys, breasts or bone.

A placental site trophoblastic tumour (PSTT) is a rare and slow-growing cancerous type of GTD. PSTTs are usually found months or years after they start to develop. PSTT starts where the placenta attaches to the wall of the uterus. These tumours can grow into the muscle wall of the uterus, but they usually don't spread to other parts of the body. Most PSTTs develop after a normal pregnancy. They can also occur after a miscarriage, an abortion or removal of a hydatidiform mole.

Epithelioid trophoblastic tumours (ETTs) are the rarest type of cancerous GTD. They most often develop after a normal pregnancy. These tumours usually occur in the uterus, but they can sometimes be found in the cervix. It can take several years for ETT to develop. So it may not cause any signs or symptoms for a long time. As a result, this type of cancer may have spread to other parts of the body (called distant metastasis) when it is diagnosed.