The ovaries are two small organs located on either side of the uterus in a woman’s body. They make hormones, including estrogen, which trigger menstruation. Every month, the ovaries release a tiny egg. The egg makes its way down the fallopian tube to potentially be fertilized. This cycle of egg release is called ovulation.
An ovarian cyst is a fluid filled pocket located on the ovary.
Cysts are very commonly found in women who have polycystic ovary syndrome and are, in fact, one of the defining characteristics of the disease. These occur when your body begins growing an egg follicle that does not fully develop or release a mature egg at the end of the menstrual cycle.
Causes
Most ovarian cysts develop as a result of the normal function of your menstrual cycle. These are known as functional cysts. Other types of cysts are much less common.
Functional cysts
Your ovaries normally grow cyst-like structures called follicles each month. Follicles produce the hormones estrogen and progesterone and release an egg when you ovulate. Sometimes a normal monthly follicle keeps growing. When that happens, it is known as a functional cyst. There are two types of functional cysts:
- Follicular cyst. Around the midpoint of your menstrual cycle, an egg bursts out of its follicle and travels down the fallopian tube in search of sperm and fertilization. A follicular cyst begins when something goes wrong and the follicle doesn’t rupture or release its egg. Instead it grows and turns into a cyst.
- Corpus luteum cyst. When a follicle releases its egg, the ruptured follicle begins producing large quantities of estrogen and progesterone for conception. This follicle is now called the corpus luteum. Sometimes, however, the escape opening of the egg seals off and fluid accumulates inside the follicle, causing the corpus luteum to expand into a cyst.
The fertility drug clomiphene (Clomid, Serophene), which is used to induce ovulation, increases the risk of a corpus luteum cyst developing after ovulation. These cysts don’t prevent or threaten a resulting pregnancy.
Functional cysts are usually harmless, rarely cause pain, and often disappear on their own within two or three menstrual cycles.
Other cysts
Some types of cysts are not related to the normal function of your menstrual cycle. These cysts include:
- Dermoid cysts. These cysts may contain tissue, such as hair, skin or teeth, because they form from cells that produce human eggs. They are rarely cancerous.
- Cystadenomas. These cysts develop from ovarian tissue and may be filled with a watery liquid or a mucous material.
- Endometriomas. These cysts develop as a result of endometriosis, a condition in which uterine endometrial cells grow outside your uterus. Some of that tissue may attach to your ovary and form a growth.
Dermoid cysts and cystadenomas can become large, causing the ovary to move out of its usual position in the pelvis. This increases the chance of painful twisting of your ovary, called ovarian torsion.
Symptoms
Some or all of the following symptoms may be present, though it is possible not to experience any symptoms:
- Abdominal pain. Dull aching pain within the abdomen or pelvis, especially on intercourse.
- Uterine bleeding. Pain during or shortly after beginning or end of menstrual period; irregular periods, or abnormal uterine bleeding or spotting.
- Fullness, heaviness, pressure, swelling, or bloating in the abdomen.
- When a cyst ruptures from the ovary, there may be sudden and sharp pain in the lower abdomen on one side.
- Change in frequency or ease of urination (such as inability to fully empty the bladder), or difficulty with bowel movements due to pressure on adjacent pelvic anatomy.
- Constitutional symptoms such as fatigue, headaches
- Nausea or vomiting
- Weight gain
Other symptoms may depend on the cause of the cysts:
- Symptoms that may occur if the cause of the cysts is polycystic ovarian syndrome may include increased facial hair or body hair, acne, obesity and infertility.
- If the cause is endometriosis, then periods may be heavy, and intercourse painful.
Complications
Most ovarian cysts are benign and naturally go away on their own without treatment. These cysts cause little, if any, symptoms. But in a rare case, your doctor may detect a cancerous cystic ovarian mass during a routine examination.
- Size. How big is it?
- Composition. Is it filled with fluid, solid or mixed? Fluid-filled cysts aren’t likely to be cancerous. Those that are solid or mixed — filled with fluid and solid may require further evaluation to determine whether cancer is present.
- Pregnancy test. A positive pregnancy test may suggest that your cyst is a corpus luteum cyst, which can develop when the ruptured follicle that released your egg reseals and fills with fluid.
- Pelvic ultrasound. In this procedure, a wand-like device (transducer) sends and receives high-frequency sound waves (ultrasound) to create an image of your uterus and ovaries on a video screen. Your doctor analyzes the image to confirm the presence of a cyst, help identify its location and determine whether it’s solid, filled with fluid or mixed.
- Laparoscopy. Using a laparoscope — a slim, lighted instrument inserted into your abdomen through a small incision — your doctor can see your ovaries and remove the ovarian cyst. This is a surgical procedure that will require you to undergo anesthesia.
- CA 125 blood test. Blood levels of a protein called cancer antigen 125 (CA 125) often are elevated in women with ovarian cancer. If you develop an ovarian cyst that is partially solid and you are at high risk of ovarian cancer, your doctor may test the level of CA 125 in your blood to determine whether your cyst could be cancerous. Elevated CA 125 levels can also occur in noncancerous conditions, such as endometriosis, uterine fibroids and pelvic inflammatory disease.
Treatment depends on your age, the type and size of your cyst, and your symptoms. Your doctor may suggest:
Watchful waiting
In many cases you can wait and be re-examined to see if the cyst goes away on its own within a few months. This is typically an option — regardless of your age if you have no symptoms and an ultrasound shows you have a small, fluid-filled cyst. Your doctor will likely recommend that you get follow-up pelvic ultrasounds at periodic intervals to see if your cyst has changed in size.
Prevention
Ovarian cysts cannot be prevented. However, routine gynecological examinations can detect ovarian cysts early. Benign ovarian cysts do not become cancerous. However, symptoms of ovarian cancer can mimic symptoms of an ovarian cyst. Thus, it is important to visit your doctor and receive a correct diagnosis. Alert your doctor to symptoms that may indicate a problem, such as:
- changes in your menstrual cycle
- ongoing pelvic pain
- loss of appetite
- unexplained weight loss
- abdominal fullness
- Age: The development of a functional ovarian cyst depends on hormonal stimulation of the ovary. A woman is more likely to develop a cyst if she is still menstruating and her body is producing the hormone estrogen. Postmenopausal women have a lower risk for developing ovarian cysts since they are no longer having menstrual periods. For this reason, many doctors recommend removal or biopsy of ovarian cysts in postmenopausal women, particularly if the cysts are larger than 1-2 inches in diameter.
- Cyst size: The size of the ovarian cyst relates directly to the rate at which they shrink. As a rule, functional cysts are 2 inches in diameter or smaller and usually have one fluid-filled area or bubble. The cyst wall is usually thin, and the inner side of the wall is smooth. An endovaginal ultrasound can reveal these features. Most cysts smaller than 2 inches in diameter are functional cysts. Surgery is recommended to remove any cyst larger than 4 inches in diameter.
