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About gestational trophoblastic tumours

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This page explains what gestational trophoblastic tumours (GTT) are. There is information about

 

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About gestational trophoblastic tumours 

Gestational trophoblastic tumours (GTTs) grow from the tissue that forms in the womb during pregnancy. They are very rare and can be non cancerous (benign) or cancerous (malignant). They include molar pregnancy, placental site trophoblastic tumour (PSTT), persistent trophoblastic disease, and choriocarcinoma. 

How gestational trophoblastic tumours develop

Usually, after a sperm fertilises an egg, new cells grow within the womb to form an embryo. As the embryo grows, its cells start to specialise. Some cells start to form the baby (foetus) and others form the placenta, which protects and nourishes the foetus during pregnancy. The first layer of cells that develops into the placenta is called the trophoblast. It produces tiny, finger like, outgrowths known as villi that attach the placenta to the lining of the womb.

In a molar pregnancy, there is a mistake when the sperm fertilises the egg. The pregnancy is abnormal and the foetus either doesn’t develop at all, or it only partly develops and can't grow normally. The villi may swell up and grow in clusters, a bit like bunches of grapes. A molar pregnancy is not cancer – it is benign. But rarely, cells from a molar pregnancy can become cancerous and the cells can then spread to other parts of the body.

Placental site trophoblastic tumours can happen after any type of pregnancy, including molar pregnancy, miscarriage, or a full term normal pregnancy. They can occur several months, or even years, later. They develop in the area where the placenta joined the lining of the womb (uterus). They can grow into the muscle layer of the womb but don’t often spread to other parts of the body.

In a persistent GTT or choriocarcinoma, some of the trophoblastic cells in the lining of the womb grow abnormally and develop into a tumour. These tumours are cancerous and can spread deeply into the wall of the womb. They can also spread beyond the womb, to other parts of the body.

Treatment that works very well is available for all types of GTTs. Nearly all of them are curable, whether they are cancerous or non cancerous.

 

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What gestational trophoblastic tumours (GTTs) are

A gestational trophoblastic tumour (GTT) is a tumour that grows from the tissue that forms in the womb during pregnancy. They are very rare. They can be non cancerous (benign) or cancerous (malignant). They include molar pregnancy, persistent trophoblastic disease, placental site trophoblastic tumour (PSTT), and choriocarcinoma. 

Although GTTs start in the womb, they behave very differently from a cancer of the womb. They are also treated differently from womb cancer. If you are looking for information about womb cancer (also known as uterine or endometrial cancer) this section is not for you. You need to go to the womb cancer section.

 

How GTTs develop

Gestation means pregnancy and trophoblast describes cells that are part of the normal development of a baby. Usually, after a sperm fertilises an egg, new cells grow within the womb to form an embryo. As the embryo grows, its cells start to specialise. Some cells start to form the baby (foetus) and others form the placenta. The placenta protects and nourishes the baby during pregnancy.

The first layer of cells that develops into the placenta is called the trophoblast. The trophoblast produces tiny, finger like, outgrowths known as villi. These villi attach the placenta to the lining of the womb. 

In a molar pregnancy, there is a mistake when the sperm fertilises the egg. The pregnancy is abnormal and the foetus either doesn’t develop at all, or it partly forms but can't grow normally. The villi may swell up and grow in clusters, a bit like bunches of grapes. Molar pregnancy is the most common type of GTT. These tumours are not cancerous – they are benign. But, rarely, a molar pregnancy can become cancerous and can spread to other parts of the body. 

Placental site trophoblastic tumours are very rare. They can happen after any type of pregnancy, including molar pregnancy, miscarriage, or a full term normal pregnancy. They can occur several months, or even years, later. They develop in the area where the placenta joined the lining of the womb (uterus). They can grow into the muscle layer of the womb but don’t often spread to other parts of the body.

In a persistent GTT or choriocarcinoma, some trophoblastic cells grow abnormally and develop into a tumour. These tumours are cancerous and can spread outside the womb.

Treatment that works very well is available for all types of GTTs. Nearly all of them are curable, whether they are cancerous or non cancerous.

 

Links to information about GTTs

 

Other terms used to describe GTT

The medical descriptions for GTT are all quite long and can sound complicated. Other terms that may be used for these types of tumours include

  • Trophoblastic disease
  • Gestational trophoblastic disease
  • Gestational trophoblastic neoplasia (GTN)
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Updated: 29 April 2014