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.
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.
Classification Ovarian cysts may be classified according
to whether they are a variant of the normal menstrual cycle, called a functional cyst,
or not. Functional
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 will rupture during ovulation. If this does not occur, a follicular cyst of
more than 2.5 cm diameter may result. Corpus luteum cysts appear after ovulation.
The corpus luteum is the remnant of the follicle after the ovum has moved to the fallopian
tubes. This normally degrades within 5–9 days. A corpus lutem that is more than 3 cm
is defined as cystic. 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.
Non-functional
Non-functional cysts may include: An ovary with many cysts, which may be found
in normal women, or within the setting of polycystic ovary syndrome.
Cysts caused by endometriosis, known as chocolate cysts.
Hemorrhagic ovarian cyst Dermoid cyst
Ovarian serous cystadenoma Ovarian mucinous cystadenoma
Paraovarian cyst Cystic adenofibroma
Borderline tumoral cysts Juvenile
Benign ovarian cysts are common in unsymptomatic premenarchal girls and found in approximately
68% of ovaries of girls 2-12 years old. Most of them are smaller than 9 mm while about
10-20% are larger macrocysts. While the smaller cysts mostly disappear within 6 months the
larger ones appear to be more persistent. In juvenile hypothyroidism multicystic ovaries
are present in about 75% of cases while large ovarian cysts and elevated ovarian tumor markes
are one of the symptoms of the Van Wyk and Grumbach syndrome.
Signs and 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, 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.
Diagnosis
Ovarian cysts are usually diagnosed by either ultrasound or CT scan, with additional endocrinological
tests. Follow-up imaging for women of reproductive
age with small simple or hemorrhagic cyst is generally not required.
There are several systems for scoring of the risk of an ovarian cyst of being an ovarian
cancer, including RMI, LR2 and SR. Sensitivities and specificities of these systems are given
in tables below: Risk of malignancy index
A widely recognized method of estimating the risk of malignant ovarian cancer based on
initial workup is the risk of malignancy index. It is recommended that women with an RMI score
over 200 should be referred to a center with experience in ovarian cancer surgery.
The RMI is calculated as follows: RMI = ultrasound score x menopausal score
x CA-125 level in U/ml. There are two methods to determine the ultrasound
score and menopausal score, with the resultant RMI being called RMI 1 and RMI 2, respectively,
depending on what method is used:
An RMI 2 of over 200 has been estimated to have a sensitivity of 74 to 80%, a specificity
of 89 to 92% and a positive predictive value of around 80% of ovarian cancer. RMI 2 is
regarded as more sensitive than RMI 1. Treatment
Cysts associated with hypothyroidism or other endocrine problems are treated by treating
the underlying condition. About 95% of ovarian cysts are benign, not
cancerous. Treatment for cysts depends on the size of
the cyst and symptoms. Pain caused by ovarian cysts may be treated
with: Pain relievers, including acetaminophen/paracetamol,
nonsteroidal anti-inflammatory drugs such as ibuprofen, or narcotic pain medicine may
help reduce pelvic pain. NSAIDs usually work best when taken at the first signs of the
pain. 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:
Persistent complex ovarian cysts Persistent cysts that are causing symptoms
Simple ovarian cysts larger than 5-10 centimeters Women who are menopausal or perimenopausal
Ovarian cyst rupture 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. References
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