An ovarian cyst is a fluid-filled sac that develops near the surface of the ovary. The ovaries are two small organs on each side of a woman's uterus that produce eggs and female hormones. Most ovarian cysts are small and benign (not cancerous). However, the larger ones can cause pain and other problems. A woman can develop one or many ovarian cysts.
Structures called follicles normally grow in the ovaries each month. They produce hormones and release an egg during ovulation. In some cases, follicles may become cysts. There are two main types:
- Functional Cyst–occurs when a normal monthly follicle does not mature properly and the egg is not released. These cysts often go away on their own within 1-3 menstrual cycles.
- Follicular Cyst–can occur after an egg is released. These cysts usually go away on their own in a few weeks. These are a type of functional cyst.
Most ovarian cysts are functional cysts and only occur during childbearing years. Many other, less common types of benign cysts can also develop from ovarian tissue. For example, women with endometriosis may develop endometriomas. Endometriosis is a condition in which tissue from the uterine lining grows outside the uterus. Endometriomas are cysts that grow from the uterine tissue on an ovary; they contain old blood.
Polycystic ovary syndrome is also associated with cysts. Women with this condition have several small cysts in their ovaries (more than 10).
A very small percentage of women have cysts that are caused by cancer.
A risk factor is something that increases your chance of getting a disease or condition.
The main risk factor for ovarian cysts is being a woman of childbearing age.
Most ovarian cysts do not cause symptoms. When they do, pelvic pain and irregular menstrual bleeding are the two most common symptoms. Pain is usually caused by:
- Direct pressure from the cysts on the ovaries and surrounding structures. This causes chronic pelvic fullness or a dull ache.
- Bleeding from a cyst into and around the ovary. This causes more intense, sharp pain.
Pain may come and go on a regular basis. Or it may become more noticeable just before or after a period or during intercourse.
Other symptoms may include:
- Urinary discomfort associated with bladder pressure or irritation
In rare cases, an ovarian cyst may become twisted and cut off its own blood supply. This can cause severe abdominal pain, vomiting, and fever. This requires immediate medical attention.
The doctor will ask about your symptoms and medical history, and perform a pelvic exam. This includes feeling the ovaries. Ovarian cysts are often found during routine pelvic exams when there are no symptoms.
If a cyst is suspected or found on physical exam, the doctor may recommend a pelvic ultrasound. This is a test that uses sound waves to create images of the ovaries, from which the doctor can determine the type and size of the cyst, and if treatment is needed.
Other tests or procedures may be used if a cyst:
- Does not go away after several menstrual cycles
- Gets larger and more painful
- Does not appear to be a simple functional cyst (has atypical features or atypical blood flow on ultrasound and Doppler exam)
Other tests may include:
- Laparoscopy–a thin, lighted tube and other small instruments are inserted through several tiny incisions in the abdomen to look at the ovaries directly, drain fluid from a cyst, or take a sample for biopsy.
- Blood test for the protein CA-125–this test may be done when a cyst is suspected of being cancerous. CA-125 is often elevated in the case of ovarian cancer; but is also elevated in many benign situations.
Treatment depends on your age, menstrual status, the size and type of the cyst, and your symptoms. The main types of treatment are:
Wait and See–this approach involves waiting a few months to see if the cyst goes away on its own.
Birth Control Pills–if you have a functional cyst, your doctor may prescribe birth control pills to help prevent other cysts from developing during the ‘wait and see’ period. If you get ovarian cysts often, birth control pills decrease the chance of new ones forming.
Laparoscopic Surgery–pelvic laparoscopy may be recommended to remove a cyst if it:
- Grows larger or reaches a size greater than two inches
- Has some solid material in it, or other atypical features
- Causes persistent or worsening symptoms
- Lasts longer than two or three menstrual cycles
If the cyst is not cancerous, often just the cyst can be removed. However, in some cases, your whole ovary may need to be removed. If the cyst is cancerous, you may have your ovary and uterus removed. This requires an open surgical procedure, rather than a laparoscopy.
Since ovarian cysts are common, and are usually painless and benign, doctors do not routinely recommend any preventive interventions. Women who have recurrent symptomatic cysts may benefit from birth control pills over the long term. Taking oral contraceptive pills for more than five years has also been shown to reduce the risk of ovarian cancer.
The best way to catch cysts early is to:
- Tell your doctor about any changes in your monthly cycles or periods
- Report pelvic and abdominal pain