Definition  

An ovarian cyst is a fluid-filled sac in the ovary. During the menstrual cycle, it is normal for a cyst to develop. Most cysts are small and benign (not cancer) and go away on their own. Larger cysts can cause pain and other problems.

Close Up of Ovary and Fallopian Tube  
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Causes  

Follicles grow in the ovaries each month during childbearing years. Each month, in an ovary, at least one egg matures in its follicle. The egg and follicle become a small functional cyst. It makes hormones and during ovulation will release an egg . In some cases, these follicles may enlarge enough to become cysts. They are also known as a functional cysts. There are two main types:

  • Follicular cysts—occurs when a follicle does not mature properly. The egg is not released. The follicle and egg develop into a cyst.
    • These cysts go away on their own within 1-3 menstrual cycles.
  • Corpus luteum cyst—occurs after an egg is released from the follicle during ovulation. Fluid builds up in the follicle and creates a cyst.
    • These cysts go away on their own in a few weeks.

Other, less common types of benign cysts can also form from ovarian tissue:

  • Dermoid cysts—made of types of tissue from other parts of the body like skin or hair. The ovary, as a reproductive organ contains many immature cells. These cell can grow into different cell types.
  • Endometriomas—endometrial tissue (lining of uterus) appears to be able to migrate from the uterus to the ovary. Cysts may grow and become filled with fluid (often blood).
  • Cystadenoma—grows from cells lining the outside of the ovary. Can become large and painful.

In a small number of cases, some of these cysts are able to undergo cancerous changes . Therefore, your doctor will assess each cyst very carefully.

Risk Factors  

The main risk factor is being a woman with a menstrual cycle.

Symptoms  

Most ovarian cysts do not cause symptoms.

An ovarian cyst may become twisted. This action may cause pain in the lower abdomen. Some cysts may also rupture releasing their fluid into the abdomen. This fluid can irritate the lining of the abdomen and cause pain. The pain may be on one or both sides of the lower abdomen.

Large cysts may cause a sensation of pressure in the abdomen. They can also cause urinary problems if they press on the bladder. Pressure on the bowel can also cause changes in bowel habits.

It is best to keep in mind that most ovarian cysts cause no symptoms. If you know you have a cyst, call your doctor promptly if any of the symptoms described above do occur.

Diagnosis  

The doctor will ask about your symptoms and medical history. A pelvic exam will also be done. Cysts are often found during routine pelvic exams when there are no symptoms.

If a cyst is suspected or found, the doctor may do a pelvic ultrasound . This is a test that uses sound waves to create images of the ovaries. Using this test, your doctor can determine:

  • Type and size of the cyst
  • Type of treatment needed (if any)

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

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 —done when a cyst is suspected of being cancerous
    • CA-125 is often elevated in the case of ovarian cancer. But it can also be elevated in benign situations.
Treatment  

Treatment depends on:

  • Age
  • Menstrual status
  • Size and type of cyst
  • Symptoms

The main types of treatment are:

Wait and See  

The doctor waits a few months to see if the cyst goes away on its own.

Medication  
Birth Control Pills  

If you have a functional cyst, your doctor may prescribe birth control pills. While taking birth control pills will not make the cyst that you have go away, the pills can help prevent further cysts from forming on your ovaries.

Pain Medication  

If your cyst is causing a lot of discomfort, your doctor may prescribe pain medicine. But, if the cyst is causing a lot of pain, it may need to be surgically removed.

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 features
  • Causes persistent or worsening symptoms
  • Lasts longer than two or three menstrual cycles
  • Disrupts blood flow

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 both ovaries and uterus removed. This requires an open surgical procedure .

If you are diagnosed with an ovarian cyst, follow your doctor's instructions .

Prevention  

Ovarian cysts are common and are usually painless and benign. Doctors do not routinely recommend preventive interventions. Birth control pills may help you if the cysts keep coming back. Taking birth control pills for more than five years has also been shown to reduce the risk of ovarian and endometrial 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.