Functional ovarian cysts

This page tells you about functional ovarian cysts. There is information on

 
 

What functional cysts are

Cysts are fluid filled sacs and there are several different types that can affect the ovary. Most are not cancerous (benign). Functional cysts are the most common type of ovarian cyst and usually develop during your childbearing years. They arise during the normal process of releasing an egg (ovulation) and are benign.

Once a month the ovary makes a number of small sacs (follicles) which hold the eggs. These follicles are full of fluid, so are a bit like small cysts. Once the egg is mature the follicle breaks open to release the egg. The egg then travels down the fallopian tube ready to be fertilised by sperm. The sac dissolves away and your body absorbs the fluid that was in it.

There are two types of functional ovarian cyst

Follicular cyst

A follicular cyst can occur when the follicle does not release the egg. Or if the follicle continues to fill with fluid. These cysts can grow to 4 or 5 cm in size, but they usually disappear on their own within a few weeks.

Corpus luteum cyst

These are less common than follicular cysts. They develop after the egg has been released. Instead of dissolving away, the tissue that is left behind (the corpus luteum) fills with fluid and reseals itself to form a sac. These can grow up to 6cm in size. They usually disappear on their own within a few months, but can occasionally split (rupture) causing sudden pain and bleeding.

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How they are diagnosed

Most functional cysts are small and don’t cause any symptoms. So they often go undiagnosed. If you do have symptoms these might include a dull pain or discomfort in your abdomen, and irregular periods. Or your doctor might discover a cyst when doing a pelvic examination or a scan for another medical reason. Tests you might have to confirm you have an ovarian cyst are

  • Ultrasound scan - this uses sound waves to build up a picture of your ovaries. Sometimes the doctor uses a probe inside the vagina to check the ovaries. This is called a vaginal ultrasound
  • Blood tests to check a protein in the blood called CA125 - raised levels of CA125 can be a sign of ovarian cysts and ovarian cancer
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How they are treated

You probably won’t need any treatment for a functional ovarian cyst. A few months after being diagnosed, you might have another ultrasound scan, to check that the cyst has gone. But if it doesn’t go away, or is getting bigger and causing symptoms, your doctor may suggest that you have it removed. This can be done by either

Laparoscopy

This is the most common way to remove a cyst. You have a small cut made near your tummy button and a tube a bit like a telescope is put inside. The surgeon removes the cyst. This operation is done under a light general anaesthetic.

Laparotomy

You might have this operation, if the cyst is larger and at risk of splitting open but this is rare. For this operation you will need a larger cut made on your tummy (abdomen) under a general anaesthetic. The whole cyst is then removed.

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