What is invasive mole and choriocarcinoma?

Invasive mole and choriocarcinoma are both types of gestational trophoblastic disease. 

Very rarely, abnormal cells or tumours can grow from the tissue that forms in the womb Open a glossary item during pregnancy. This is called gestational trophoblastic disease (GTD). GTD can be cancerous or non cancerous (benign). Invasive mole and choriocarcinoma are both cancerous types of GTD.

Invasive mole and choriocarcinoma are usually found in the womb. But they can spread to other areas of the body and might cause symptoms there.

Invasive mole

A molar pregnancy happens when the fertilisation of the egg by the sperm goes wrong. This leads to the growth of abnormal cells or clusters of water filled sacs inside the womb. Only about 1 in every 600 pregnancies in the UK is a molar pregnancy.

Usually any molar cells left after treatment will die off by themselves. Rarely they can keep growing and become cancerous. This is called an invasive mole or persistent trophoblastic disease (PTD).

Even a very small amount of molar tissue anywhere in the body can grow and cause problems. Like other cancers, an invasive mole can spread to other parts of the body. But it has a cure rate of nearly 100%.

The treatment for an invasive mole is usually chemotherapy Open a glossary item.

Choriocarcinoma

A choriocarcinoma is a cancer that happens when 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 of the growing baby (foetus). Carcinoma means cancer in the epithelial cells which cover or line a body organ.

Choriocarcinoma is more common after a molar pregnancy. It can also happen after a full term pregnancy, miscarriage, ectopic pregnancy or abortion.

A choriocarcinoma can develop some months or even years after pregnancy. It can be difficult to diagnose because it is so rare. It can grow quickly and might cause symptoms within a short period of time.

Treatment for choriocarcinoma is usually chemotherapy. Or sometimes surgery. Women with a low risk score can usually be cured even if it has spread to other parts of the body.

Your doctor and specialist nurse will talk to you about the best treatment options for you. 

  • Diagnosis and management of gestational trophoblastic disease: 2025 update
    H Y S Ngan and others  
    The International Journal of Gynecology & Obstetrics. 2025 

  • The Management of Gestational Trophoblastic Disease (4th edition)
    Royal College of Obstetricians and Gynaecologists, September 2020

  • Gestational Trophoblastic Disease (5th Edition)
    International Society for the Study of Trophoblastic Diseases, 2022

  • Practical Guidelines for the Treatment of Gestational Trophoblastic Disease: Collaboration of the European Organisation for the Treatment of Trophoblastic Disease (EOTTD)–European Society of Gynaecologic Oncology (ESGO)–Gynecologic Cancer InterGroup (GCIG)–International Society for the Study of Trophoblastic Diseases (ISSTD)

    C Lok and others

    Journal of Clinical Oncology, 2025 

  • Epidemiology, diagnosis, and treatment of gestational trophoblastic disease: A Society of Gynecologic Oncology evidenced-based review and recommendation

    N S Horowitz and others

    Gynecologic Oncology, 2021. Volume 163, Issue 3, Pages 605-613

Last reviewed: 
08 Sep 2025
Next review due: 
08 Sep 2028

Related links