An ovarian cyst is any collection of fluid, surrounded by a very thin wall, within an ovary. Any ovarian follicle that is larger than about two centimeters is termed an ovarian cyst. Such cysts range in size from as small as a pea to larger than an orange.
Most ovarian cysts are functional in nature and harmless (benign).
Ovarian cysts affect women of all ages. They occur most often, however, during a woman's childbearing years.
Some ovarian cysts cause problems, such as bleeding and pain. Surgery may be required to remove cysts larger than 5 centimeters in diameter.
Ovarian cysts may be classified according to whether they are a variant of the normal menstrual cycle, called a functional cyst, or not.
Functional cysts form as a normal part of the menstrual cycle. Such cysts may include:
Follicular cyst, the most common type of ovarian cyst. In menstruation, a follicle containing the ovum (unfertilized egg) will rupture during ovulation. If this does not occur, a follicular cyst of more than 2.5 cm diameter may result.
Thecal cysts occur within the thecal layer of cells surrounding developing oocytes. Under the influence of excessive hCG, thecal cells may proliferate and become cystic. This is usually on both ovaries.
A warm bath, or heating pad, or hot water bottle applied to the lower abdomen near the ovaries can relax tense muscles and relieve cramping, lessen discomfort, and stimulate circulation and healing in the ovaries.
Combined methods of hormonal contraception such as the combined oral contraceptive pill – the hormones in the pills may regulate the menstrual cycle, and prevent the formation of follicles that can turn into cysts.(American College of Obstetricians and Gynecologists, 1999c; Mayo Clinic, 2002e) However, a Cochrane review in 2011 concluded oral contraceptives are of no benefit in treating already present functional cysts.
Also, limiting strenuous activity may reduce the risk of cyst rupture or torsion.
Cysts that persist beyond two or three menstrual cycles, or occur in post-menopausal women, may indicate more serious disease and should be investigated through ultrasonography and laparoscopy, especially in cases where family members have had ovarian cancer. Such cysts may require surgical biopsy. Additionally, a blood test may be taken before surgery to check for elevated CA-125, a tumor marker, which is often found in increased levels in ovarian cancer, although it can also be elevated by other conditions resulting in a large number of false positives.
For more serious cases where cysts are large and persisting, doctors may suggest surgery. This may involve removing the cyst, or one or both ovaries. Features that may indicate the need for surgery include:
A rupture of an ovarian cyst is usually a self-limiting, and only requires expectant management and analgesics. The main symptom is abdominal pain, but can also be asymptomatic. The pain may last from a few days to several weeks.