Ovarian cysts

An ovarian cyst is a fluid-filled sac that develops in an ovary (the female gland that produce sex hormones and eggs for reproduction). Ovarian cysts are very common and rarely cancerous. They may occur at any age, but they're most common during the reproductive years.


Anatomy
The ovaries are the organs that produce eggs for reproduction and most of the female sex hormones (estrogen and progesterone). These hormones control such physical characteristics as breasts, body shape and body hair. They also play a role in menstrual cycles and pregnancy.
The menstrual cycle has three phases: follicular, ovulatory and luteal.

The follicular phase begins with the first day of your cycle -- the first day of your period. Estrogen and progesterone levels begin to rise, causing a follicle to develop in the ovary and the uterine lining to thicken. The follicle holds the egg that will be released when it reaches maturity, and the uterine lining thickens in preparation for a fertilized egg. The length of the follicular phase varies but typically lasts about 10 to 18 days.

Ovulation occurs when the follicle releases the mature egg, usually on about day 14 of a 28-day cycle. This is the ovulatory stage.

If the mature egg is not fertilized, it will break down and the cervical mucus may become thick and sticky. This phase, known as the luteal phase, begins on about day 15 to 16 and typically lasts about 14 days. Then, menstruation occurs.


Causes/associated factors
There are different types of ovarian cysts. For example:
Functional cysts are the most common type of ovarian cysts. They develop during the menstrual cycle, typically cause few symptoms and usually disappear on their own within one to three months. A follicular cyst is a functional cyst that develops during the follicular phase of the cycle. Instead of releasing the mature egg at ovulation, the follicle retains the egg and continues to grow, developing into a cyst. A corpus luteum cyst is a functional cyst that develops from the follicle after ovulation. After the egg is released, what remains of the follicle (the corpus luteum) usually dissolves. Occasionally, however, the corpus luteum persists and develops into a cyst.

Dermoid cysts are another type of cyst. In addition to greasy liquid, they may contain strange things such as teeth, hair or cartilage. They may grow up to six inches in size and can twist off the blood supply to the ovary. Dermoid cysts nearly always require surgical removal.

Endometriomas are cysts formed by endometrial tissue (the tissue that lines the uterus). In a condition called endometriosis, endometrial tissue grows outside the uterus. Endometriomas form when this tissue grows on the ovary. They are typically filled with dark old blood and are often referred to as "chocolate cysts." Endometriomas can be drained with a needle and syringe.

Most cysts are benign and cause few symptoms. Occasionally, however, an ovarian cyst may be cancerous.


Signs/symptoms
Most ovarian cysts cause no symptoms for most women and often go unnoticed. If a cyst continues to grow, however, it may produce lower abdominal pain or a sensation of abdominal fullness or bloating. Some women may have pain only on the side of the affected ovary. If the cyst becomes large, begins to bleed, bursts, or twists and obstructs blood flow to the ovary, symptoms can be severe. A large cyst can also delay or change menstrual flow or cause pain during sex.

Diagnosis
Small cysts that cause no symptoms may be detected during a routine annual pelvic exam. In other situations, your symptoms may bring you to the doctor. He or she may first want to rule out other conditions, such as ectopic pregnancy, a pelvic infection, endometriosis, ovarian cancer, diverticulitis or appendicitis. Depending on your age, symptoms and the size of the cyst, you may need various tests. For example:
Your doctor may do a vaginal or abdominal ultrasound (using sound waves to create an image of internal body parts) to create a picture of your ovaries and other organs. With a vaginal ultrasound, a small transducer that will transmit the sound waves is inserted into your vagina. With an abdominal ultrasound, the transducer will be moved over your abdomen. An ultrasound is not painful and usually takes about 30 minutes. In some cases, both types of ultrasound are done.

Your doctor may order a blood test to measure the amount of antigen 125 (CA 125) in your blood. This protein, which is produced by a variety of cells, is sometimes found in elevated levels in the blood, urine or body tissues of people who have certain types of cancer, particularly ovarian cancer. Elevations of CA 125 are also associated with other conditions, such as endometriosis or pelvic inflammatory disease.

If further evaluation is needed, your doctor may drain the fluid from the cyst, do a biopsy (take a tissue sample for further examination) or remove the cyst completely using a laparoscope (a thin tube equipped with a camera lens and light).


Treatment
If you're of childbearing age and the cyst is small or doesn't cause any symptoms, your doctor may suggest waiting two to three menstrual cycles to see if the cyst shrinks on its own. If there's no improvement, your doctor may prescribe birth control pills to suppress cyst development in the ovaries. The pills are usually taken for short periods of time to prevent ovulation, which makes the cysts less likely to grow.
If the cyst is large or causing troublesome symptoms, the cyst and possibly even the affected ovary may need to be removed. Before menopause, remember that it's still possible to become pregnant as long as you have one ovary. Again, removing the cyst can usually be done through laparoscopy, a minor surgical procedure that allows the doctor to directly view organs in the abdominal cavity.

After menopause, any ovarian mass needs careful evaluation to rule out ovarian cancer. Although rare, ovarian cancer is more common in older women.



Complications
Ovarian cysts may cause twisting, rupture or bleeding of the ovary, a potentially life-threatening situation that often requires emergency abdominal surgery. Ovarian cysts may also contribute to infertility or cause pelvic adhesions (the joining of internal tissues).

Pregnancy-specific information
Ovarian cysts may develop during pregnancy. As part of your routine prenatal care, notify your doctor of any unusual abdominal symptoms.

Senior-specific information
The ovaries shrink after menopause and should not be felt during a physical exam. If an ovarian growth is detected after menopause, thorough evaluation is necessary to rule out ovarian cancer.

Prevention
Taking birth control pills significantly decreases the development of functional ovarian cysts. Doing so during the later reproductive years also decreases the risk of developing uterine and ovarian cancer.