Everything you need to know about ovarian cysts

Dr Juliet McGrattan (MBChB)
·9-min read
Photo credit: Jasenka Arbanas - Getty Images
Photo credit: Jasenka Arbanas - Getty Images

From Netdoctor

Concerned about ovarian cysts? An ovarian cyst is a fluid-filled sac that commonly forms on the ovaries. Most ovarian cysts are harmless and resolve on their own, but sometimes they can become large, cause pain and may even be cancerous.

How do you know if you have a cyst that needs treatment and when should you see a doctor? And can having an ovarian cyst affect your fertility and what happens if you have a cyst while you are pregnant?

Dr Juliet McGrattan looks at everything from cyst symptoms to removal in our complete guide to ovarian cysts:

What is an ovarian cyst?

A cyst is simply a small sack or pocket that is filled with something, usually fluid, air or a thick or semi-solid substance. Cysts can develop anywhere in the body, most commonly on the skin. Ovarian cysts are usually filled with fluid and they can grow within the ovary itself or attached to the outside.

Types of ovarian cysts

There are two types of ovarian cysts:

  1. Functional cysts: these are the most common type of cyst and they form as a result of the normal menstrual cycle. A follicle that usually ruptures during ovulation might just carry on growing either before (simple cyst) or after (luteal cyst) it has released its egg. Functional cysts don’t last long, they usually resolve quickly and are harmless.

  2. Pathological cysts: these form when cells multiply and overgrow and form tumours. These can be malignant (cancerous) but are usually benign (non-cancerous) and are rarer than functional cysts. 95 per cent of pathological cysts are benign and there are many different types including dermoid cysts and cystadenomas.

Dermoid cysts

Also called teratomas, dermoid cysts are congenital (present from birth) and may run in families. They aren’t linked to the menstrual cycle and form from embryonic cells that have the potential to develop into any type of cell. This means dermoid cysts sometimes contain hair, teeth, bone or skin.

Dermoid cysts can grow large, sometimes up to 15cm in diameter. They are most commonly found in women under 40 and are often discovered by chance during a scan or examination for another condition.

Cystadenomas

These form from the cells of the outer part of the ovary and are more common in women over 40. The first type is called a serous cystadenoma which usually stays quite small whereas the second type, a mucinous cystadenoma can grow very large, up to 30 cm in diameter. Both types can twist, rupture and cause symptoms by pressing on the structures around them such as the bladder or bowel.

Endometriomas

Endometriosis is a condition where tissue from the endometrium (lining of the womb) grows at other locations in the body such as the bowel, fallopian tubes or on the ovary where it can develop into a cyst. Endometriomas are sometimes called ‘chocolate cysts’ because they’re filled with old, brown blood.

Polycystic ovaries

Sometimes multiple cysts can develop on an ovary and if there are more than 12 it is called a polycystic ovary. Polycystic ovary syndrome (PCOS) is a condition where multiple cysts develop on the ovaries and there other symptoms and signs due to an abnormal balance of sex hormones including oestrogen and testosterone.

PCOS signs include acne, weight gain, body and facial hair growth, lack of periods (amenorrhoea) and difficulty conceiving. These cysts however are usually much smaller than functional or pathological cysts and should be considered as a separate condition.

Who is at risk of ovarian cysts?

Any woman can develop cysts on her ovaries. Functional cysts are linked to the menstrual cycle so are more common in women who are having periods. Pathological cysts, including cancerous cysts are more likely in women who have gone through the menopause.

Cysts are more prone to develop at times of hormonal change such as during pregnancy or while taking a progesterone based contraceptive, for example, the progesterone-only pill, contraceptive implant or an intrauterine system (IUS). They are also more common in women who are receiving hormones as part of fertility treatment or taking hormonal therapy for breast cancer.

Women who have polycystic ovary syndrome or endometriosis have an increased risk of developing ovarian cysts.

Ovarian cyst symptoms

You may not get any symptoms at all from an ovarian cyst, particularly if it is a small one. When cysts do cause symptoms they can affect you in a number of ways including:

  • Pain low in the abdomen or on the same side as the cyst. This may be mild and niggly or sudden and severe if a cyst twists or ruptures.

  • Pain during sex, usually during penetration.

  • Change in your bowel habit including constipation.

  • Needing to pass urine more frequently.

  • Bloating.

  • Feeling full easily even when you haven’t eaten much

  • A change in your periods – they have become more or less frequent, heavier or lighter or more painful than usual.

You should see your doctor if you are experiencing any of the above symptoms. They may not be caused by an ovarian cyst, for example you may need to pass urine more often if you have a urine infection, but it is important to have the correct diagnosis.

Photo credit: SDI Productions - Getty Images
Photo credit: SDI Productions - Getty Images

Ovarian cyst diagnosis

Ovarian cysts are often found co-incidentally during an examination or investigation for another condition, most commonly during an ultrasound scan. A doctor may also feel a large cyst during a pelvic examination.

An ultrasound scan is the standard first test to check for an ovarian cyst. An ultrasound probe may be inserted into the vagina to give a clearer view of the ovaries. This can show the location and size and give an indication as to what the cyst is filled with which can help in diagnosing the type of cyst.

Further tests are required if:

  • There is a suspicion that the cyst is malignant (cancerous) because of its characteristics and appearance.

  • A woman is post-menopausal when the risk of malignant cysts is higher.

  • The cyst is causing significant symptoms such as pain or bleeding.

  • A diagnosis of a functional cyst has been made but the cyst is not going away.

  • A diagnosis can’t be made.

Further tests include more detailed scans such as a CT or MRI. A blood test called CA125 can be helpful alongside the ultrasound scan to determine the risk of cancer. A cyst which looks benign (non- cancerous) on an ultrasound and a normal CA125 level makes the likelihood of cancer small. A high CA125 does not always mean a cyst is cancerous because it can be elevated by many other conditions including menstruation and endometriosis.

Ovarian cyst complications

While most cysts won’t cause any problems and will simply resolve, there are some complications that can arise from an ovarian cyst:

  1. Torsion: this is when a cyst twists – it may cut off its own blood supply by doing so but it may also cause the ovary to twist and lead to ovarian torsion. Pain becomes severe and emergency surgery is needed.

  2. Rupture: if a cyst bursts it spills its contents into the abdominal and pelvic cavities. This causes sudden and severe pain. The bigger the cyst, the higher the risk of rupture.

  3. Pressure: large cysts can press on surrounding organs such as the bladder and bowel and cause symptoms such as needing to pass urine frequently or constipation.

  4. Hormones: there are certain types of ovarian cyst which produce sex hormones. They are rare but can lead to symptoms such as excess hair growth if the cyst produces testosterone.

  5. Cancer: only around 5 per cent of pathological ovarian cysts are malignant (cancerous) and the risk is higher for women who are post-menopausal.

Ovarian cyst treatment

Most functional cysts will go away on their own after one or two periods and don’t need treatment. A follow up ultrasound might be done as a check. Sometimes the combined oral contraceptive pill might be used to prevent ovulation and therefore stop further functional cysts forming if they are recurrent.

Larger cysts that are causing symptoms or those where cancer is suspected need to be removed by surgery. Where possible this is done by laparoscopy (key hole surgery) but sometimes a laparotomy where the abdomen is cut open during a general anaesthetic is required. These procedures are usually elective (planned) surgery but if a cyst has twisted or ruptured they may be done as emergency surgery.

Ovarian cysts and the menopause

Ovarian cysts are common after the menopause. This may be partly due to the fact that more women are having scans for other health reasons and cysts are found incidentally.

Cysts which develop after the menopause need to be carefully evaluated. Functional cysts develop as part of the menstrual cycle so once this has stopped, pathological cysts are more common and the risk of ovarian cancer increases. The CA125 blood test and ultrasound scans are the first steps in investigation and further tests and follow up scans will be arranged if there is any doubt about the diagnosis.

Ovarian cysts and fertility

Ovarian cysts don’t usually affect a woman’s ability to conceive. If conditions such as endometriosis or polycystic ovary syndrome are the cause of cysts, then fertility may be lower. If you have these conditions and want to get pregnant, make an appointment with your doctor to discuss what you can do to improve your chances.

Ovarian cysts and pregnancy

It’s not unusual for an ovarian cyst to be spotted during ultrasound pregnancy scans. Thankfully most of them will resolve and not interfere with the pregnancy at all. Even if a cyst doesn’t go away and begins to grow it usually doesn’t cause any problems.

Follow up scans might be arranged to monitor the cyst. Each case will be taken individually and if there is concern about ovarian cancer, an ovarian torsion or a cyst is particularly large then further treatment including possible surgery will be discussed. Sometimes an ovarian cyst can be removed when a baby is delivered by caesarean section.

Sex after ovarian cyst removal

After a laparoscopy (key hole surgery) to remove an ovarian cyst it’s best to rest and do very little generally for around a week after your operation. It’s safe to then have sex again as soon as you feel comfortable to do so. It’s not unusual to get some vaginal discharge or light bleeding following a laparoscopy so you might prefer to wait until this has settled.

A laparotomy, where the tummy is cut open, is a bigger operation and you should avoid penetrative sex for about six weeks. This will allow time for internal and external tissues to heal. Don’t be concerned if you don’t feel like sex though, this can be normal after surgery.

Last updated: 18-11-2020

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