Explaining persistent trophoblastic disease and choriocarcinoma

Persistent trophoblastic disease is when women who have had treatment to remove a molar pregnancy still have some molar tissue left behind. Even a very small amount of molar tissue anywhere in the body can grow and cause problems. Persistent trophoblastic disease can spread to other parts of the body like a cancer but has a cure rate of nearly 100%. The treatment for persistent trophoblastic disease is usually chemotherapy.

A choriocarcinoma is a cancer, but it is very rare and usually curable. It happens if cells that were part of a normal pregnancy or a molar pregnancy become cancerous. ‘Chorio’ refers to the word chorion, which is the outer covering (membrane) of the growing baby (foetus). Carcinoma means a cancer in the epithelial cells which cover or line a body organ.

Normal pregnancies include

• Pregnancies that have reached full term and delivered a normal baby
• Miscarriages
• Ectopic pregnancies
• Pregnancies that have been ended by a termination.

Although choriocarcinoma can happen after any type of pregnancy, it is very rare and only happens in about 1 in every 50,000 to 100,000 pregnancies. It is more likely to happen after a molar pregnancy.

You can develop a choriocarcinoma months or even years after you were last pregnant and this can make it difficult to diagnose, because it is so unexpected. Choriocarcinomas can grow quickly and may cause symptoms within a short period of time. They are more likely to spread to other parts of the body than other types of gestational trophoblastic disease but are very likely to be cured by chemotherapy treatment.