Ovarian cysts

Learn about what ovarian cysts are, the different types of cyst, when they can develop and how to get them checked.

Ovarian cysts are fluid-filled pockets called sacs that can form in the ovaries. They are very common and can affect women of any age, although they are more frequent in women of childbearing age because they are linked to ovulation. Often a cyst develops and disappears without the woman even knowing that she had one. Cysts in pre-menopausal women can produce symptoms similar to those for ovarian cancer but are not known to increase the risk of ovarian cancer. 

Types of ovarian cyst

The most common type of cyst is called a functional cyst. Other types of cysts include:

  • polycystic ovaries (numerous cysts sitting under the surface of the ovaries)
  • cysts caused by endometriosis, also known as endometriomas – this is a condition where the lining of the womb (endometrium) grows outside the body of the womb
  • cystenadomas and dermoid cysts (containing a mix of different tissues).

Managing functional cysts

The approach to managing functional cysts will depend on a number of factors, mainly your age, symptoms and your medical and family history. If you're experiencing symptoms because of a cyst, your GP may recommend a CA125 blood test and transvaginal ultrasound (TVU). The result of these will be combined with other factors, including whether you've been through the menopause yet, to calculate the likelihood/chance (risk) of the cyst being malignant (cancerous).

Many cysts will disappear on their own. Others that are considered low-risk will be monitored every three to six months by further ultrasound scans. Surgery is only considered if the cyst has the potential for being cancerous, or because it's large and could cause complications or uncomfortable symptoms.


A tumour (also known as a neoplasm) is any abnormal mass of tissue (collection of cells). Like a cyst, a tumour can form in any part of the body. A tumour can be benign (non-cancerous), malignant (cancerous) or borderline (between malignant and benign).

Non-cancerous tumours

Benign (non-cancerous) tumours may cause symptoms both in most cases they do not come back after surgical removal (having an operation.) Cells in benign tumours do not spread to other parts of the body.

Cancerous tumours

Malignant (cancerous) tumours are made up of cells that grow out of control. Cells in these tumours can invade nearby tissues and spread to other parts of the body. Sometimes cells move away from the original (primary) cancer site and spread to other organs and areas through the bloodstream or lymphatic vessels (tiny vessels similar to blood vessels passing clear fluid towards the heart) where they can continue to grow and form another tumour at that site. This is known as metastatic or secondary cancer. Metastases keep the name of the original cancer location, so ovarian cancer that has spread to the liver is still called ovarian cancer.

Borderline tumours

Borderline tumours are rare types of growths, and although the cells look abnormal, they rarely have the tendency to grow out of control.

To determine whether a cyst or tumour is benign, malignant or borderline, a sample of the affected tissue – or, in some cases, the entire suspicious lump – is removed and studied under a microscope. This is known as a biopsy. In most cases, this can be done using a needle under a CT scan or ultrasound scan with local anaesthesia, but occasionally a tummy/abdomen cut (laparotomy) or keyhole operation (laparoscopy) is necessary under general anaesthesia. 


Next review: May 2021

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