Patient education: Ovarian cysts (Beyond the Basics)

OVERVIEW — Ovarian cysts are fluid-filled sacs that develop in or on the ovary (figure 1). They are common and can happen at any age. Some people with ovarian cysts have pain or pelvic pressure, while others have no symptoms.

Fortunately, most ovarian cysts do not require surgical removal and are not caused by cancer. Cysts can vary in size from less than one centimeter (one-half inch) to greater than 10 centimeters (4 inches).

This topic discusses the various causes of ovarian cysts, how ovarian cysts are diagnosed, and what follow-up testing and/or treatment might be recommended.

CAUSES — The most common causes of ovarian cysts depend upon whether or not you are still having menstrual periods.

In people who still have monthly periods ("premenopausal"), the most common causes of ovarian cysts include:

●Ovulation – "Functional" ovarian cysts develop when a follicle (sac) grows, but does not rupture to release the egg. These cysts usually resolve without treatment.

●Dermoid cysts – Dermoid cysts (teratomas) are one of the most common types of cysts found in females between age 20 and 40 years. A dermoid cyst is made up ovarian "germ cells" and can contain teeth, hair, or fat. Most dermoid cysts are benign, but rarely, they can be cancerous.

●Polycystic ovary syndrome (PCOS) – In PCOS, the ovary has many small cysts. These cysts do not need to be removed or treated with medication, but people with PCOS may need treatment for other related problems, such as irregular periods. (See "Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics)".)

●Endometriosis – People with endometriosis can develop a type of ovarian cyst called an endometrioma, or "chocolate cyst." (See "Patient education: Endometriosis (Beyond the Basics)".)

●Pregnancy – An ovarian cyst normally develops in early pregnancy, to help support the pregnancy until the placenta forms. In some cases, the cyst stays on the ovary until later in the pregnancy.

●Severe pelvic infections – Severe pelvic infections may spread to involve the ovaries and fallopian tubes. As a result, pus-filled cysts form close to the ovaries and/or fallopian tubes.

●Noncancerous growths

●Cancer – Cancer is a relatively uncommon cause of ovarian cysts in people who have not yet been through menopause; less than 1 percent of new growths on or near the ovary are related to ovarian cancer.

In people who no longer have menstrual periods ("postmenopausal"), the most common causes of ovarian cysts include:

●Noncancerous growths

●Fluid collection in the ovary

●Cancer – New growths on or around the ovary in are somewhat more likely to be caused by cancer than in those who still have monthly periods.

Do I have ovarian cancer? — It's common to worry about the possibility of cancer after being diagnosed with an ovarian cyst. While there are many things besides cancer that can cause cysts, your health care provider can talk to you about your risk of cancer and

Ovarian cancer is more likely in people who have:

●A genetic predisposition to ovarian cancer (eg, family history of ovarian or related cancers)

●A previous history of breast or gastrointestinal cancer

●A cyst that appears complex (a cyst with solid areas, nodule on the surface, or multiple fluid-filled areas)

●A fluid collection (called ascites) found in the pelvis or abdomen during the imaging test

However, it’s important to know that people without cancer may also have these characteristics. In most cases, further testing will be recommended to gauge the likelihood of cancer.

If your provider is concerned that you could have ovarian cancer, they may recommend that you see a specialist called a gynecologic oncologist for testing and treatment if needed. (See "Patient education: Treatment of ovarian cancer (Beyond the Basics)".)

SYMPTOMS — Ovarian cysts may be either symptomatic or asymptomatic. When symptoms do happen, they usually involve pain or pressure in the lower abdomen on the side of the cyst. This pain may be dull or sharp; it may be constant or come and go.

Crampy lower abdominal pain is not usually related to ovarian cysts. If you have an ovarian cyst that ruptures, you may experience a sudden sharp pain, which can be severe. Torsion (twisting) of an ovary can cause pain along with nausea and vomiting.

Abnormal periods or vaginal bleeding is not usually related to ovarian cysts.

DIAGNOSIS — Sometimes, an ovarian cyst is found or suspected during a pelvic examination. However, an imaging test is necessary to confirm the diagnosis. Blood tests may also be done depending on the situation.

Imaging tests — The imaging test most commonly used is a pelvic or "transvaginal" ultrasound. This involves inserting a probe into the vagina to create pictures of your ovary and the surrounding area. This provides information about the cyst's size, location, and other important characteristics.

A computed tomography (CT) scan or magnetic resonance imaging (MRI) scan is also sometimes used, but these tests are less common.

Blood tests — If imaging tests find that you have an ovarian cyst, your health care provider might order blood tests to help determine the nature of the cyst. Depending on your situation, blood tests might include one or more of the following:

●Pregnancy testing – Your provider might recommend a pregnancy test (blood or urine) if there is a possibility that you could be pregnant. Ovarian cysts are common during pregnancy.

●Cancer antigen 125 (CA 125) – This test is sometimes recommended in people with ovarian cysts. CA 125 is a protein in the blood that can go up when a person has ovarian cancer. (See "Patient education: Screening for ovarian cancer (Beyond the Basics)".)

It’s important to know that ovarian cancer cannot be diagnosed based upon the results of a CA 125 test. Also, noncancerous conditions can cause CA 125 to be elevated, including endometriosis, uterine fibroids, pelvic infections, heart failure, and liver and kidney disease. As a result, measurement of the CA 125 is not recommended in every case:

•CA 125 is often recommended if you are postmenopausal and have an ovarian cyst.

•CA 125 may be recommended if you are premenopausal and have an ovarian cyst that appears very large or suspicious for cancer on ultrasound.

•CA 125 is not usually recommended if you are premenopausal and have ovarian cysts that are small and do not appear suspicious for cancer.

●Other blood tests – Your provider may also recommend other blood tests.

Next steps — Depending upon your age, symptoms, test results, and family history, your health care provider may recommend either watchful waiting or surgery. (See 'Treatment' below.)

TREATMENT — Ovarian cysts do not always require treatment. In people who still have monthly periods, ovarian cysts often resolve on their own within one to two months without treatment. In people who have been through menopause, ovarian cysts are less likely to resolve.

If a cyst is large, causing pain, or appears suspicious for cancer, treatment usually involves surgery to remove the cyst or the entire ovary.

Watchful waiting

Before menopause — If you have not yet been through menopause, watchful waiting usually involves monitoring for symptoms (pelvic pain or pressure) and repeating the pelvic ultrasound after about six weeks. If your cyst does not get bigger, or if it resolves during the period of watchful waiting, you will most likely not need surgery. Your health care provider might suggest taking birth control pills during this time; this can help prevent new ovarian cysts from developing.

If a cyst decreases in size or does not change, the ultrasound is often repeated at regular intervals until your health care provider is certain that the cyst is not growing. If the cyst resolves, no further testing or follow-up is required. (See 'Follow-up' below.)

After menopause — If you have been through menopause, the decision to undergo watchful waiting depends upon the results of your initial testing (ultrasound and cancer antigen 125 [CA 125]). If your cyst does not appear to be cancerous, watchful waiting may be an option; this typically involves a pelvic ultrasound and measurement of CA 125 at regular intervals (example: in 6 weeks, 12 weeks, and then every 3 to 6 months for 1 year), or until the cyst resolves. However, ovarian cysts do not always resolve in people who have been through menopause.

If your CA 125 levels increase or the cyst grows or changes in appearance, your provider may recommend surgery to remove the cyst.

Surgery — Surgery may be recommended in the following situations:

●A cyst is causing persistent pain or pressure, or may rupture or twist.

●A cyst appears on ultrasound to be caused by endometriosis and is removed for fertility reasons.

●Large cysts (>5 to 10 cm) are more likely to require surgical removal compared with smaller cysts. However, a large size does not predict whether a cyst is cancerous.

●If the cyst appears suspicious for cancer (based on tests) or if you have risk factors for ovarian cancer.

●If the suspicion for ovarian cancer is low but the cyst does not resolve after several ultrasounds, you may choose to have it removed after a discussion with your health care provider. However, surgical removal is not usually necessary in this case.

Surgery to remove ovarian cyst — If surgery is needed to remove an ovarian cyst, the procedure is usually done in a hospital or surgical center. Whether the surgery involves removing only the cyst or the entire ovary depends upon your age and what is found during the procedure.

For example:

●If there is suspicion of cancer, the whole ovary must be removed. This is because cutting into a cancerous cyst could cause the cancer to spread. In some cases, the whole ovary is removed and the cyst turns out to be benign. Having only one ovary removed will not cause you to go through menopause and will not cause infertility.

●If the cyst appears noncancerous and is small, it may be removed laparoscopically (through several small incisions). With laparoscopic surgery, you may be able to go home the same day.

●If the cyst is large or appears suspicious for cancer, it may be necessary to have a larger incision (called a laparotomy). The surgeon may need to remove the entire ovary and surrounding tissues. You will need to stay in the hospital for one or more nights after a laparotomy.

FOLLOW-UP — After an ovarian cyst resolves, you will not need further imaging tests if you do not have symptoms.

Some types of ovarian cysts are more likely to recur than others. These include endometriomas and functional ovarian cysts. If you still have monthly periods and are concerned about recurrent cysts, taking birth control pills or another hormonal form of birth control may help to prevent ovarian cysts from developing. (See "Patient education: Hormonal methods of birth control (Beyond the Basics)".)

WHERE TO GET MORE INFORMATION — Your health care provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Ovarian cysts (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics)
Patient education: Endometriosis (Beyond the Basics)
Patient education: Treatment of ovarian cancer (Beyond the Basics)
Patient education: Screening for ovarian cancer (Beyond the Basics)
Patient education: Hormonal methods of birth control (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Endometriosis: Management of ovarian endometriomas
Adnexal mass: Differential diagnosis
Evaluation and management of ruptured ovarian cyst
Anesthesia for nonobstetric surgery during pregnancy
Oophorectomy and ovarian cystectomy
Ovarian and fallopian tube torsion
Approach to the patient with an adnexal mass
Adnexal mass: Ultrasound categorization
Ovarian germ cell tumors: Pathology, epidemiology, clinical manifestations, and diagnosis

The following organizations also provide reliable health information.

●National Library of Medicine

(https://medlineplus.gov/healthtopics.html)