Placental site trophoblastic tumour

A placental site trophoblastic tumour is a type of gestational trophoblastic tumour (GTT for short). GTT is the term doctors use to describe a group of conditions in which abnormal cells grow inside a woman’s womb.

It is important to realise that GTTs are not the same as womb cancer. In womb cancer the cancer develops from the cells that form the womb. In GTT the tumour develops from tissue that forms in the womb when you are pregnant. These tumours develop in cells that grow to form the placenta (trophoblast cells).

Placental site trophoblastic tumours (PSTTs) are one type of GTT. PSTTs 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, after a previous pregnancy. 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. They are slow growing tumours and are usually curable. They are extremely rare, accounting for less than 1 in 100 (1%) of all GTTs. Fewer than 5 women are diagnosed in the UK with PSTT each year.

The main symptoms of PSTTs are absent periods (amenorrhoea) or irregular bleeding from the vagina. 

Your main treatment will be surgery and your specialist will usually recommend a hysterectomy. If your doctor can remove the whole tumour in this way it should cure the condition. Surgery is the main treatment for PSTT because chemotherapy does not always work as well as it does for other types of gestational tumours. However you will need chemotherapy after surgery if you have PSTT that has spread to another part of your body, such as the lungs.

After treatment your specialist will monitor you closely. You may need ultrasound scans, MRI scans or CT scans to check how well the treatment has worked and to monitor your progress.

You can find more detailed information about the treatments for gestational trophoblastic tumours, in the gestational trophoblastic tumour section of CancerHelp UK.