What Are the Types of Ovarian Cysts?
The most common types of ovarian cysts are:
Follicular cyst: A follicular cyst is simple cyst can form when ovulation does not occur or when a mature follicle involutes (collapses on itself). A follicular cyst usually forms at the time of ovulation, and can grow to about 2-3 inches in diameter. The rupture of this type of cyst can create sharp severe pain on the side of the involved ovary. This sharp pain (sometimes called mittelschmerz) occurs in the middle of the menstrual cycle, during ovulation. About one-fourth of women with this type of cyst experience pain. Usually, these cysts produce no symptoms and disappear by themselves within a few weeks or months.
Corpus luteum cyst: A corpus luteum cyst is a functional ovarian cyst that occurs after an egg has been released from a follicle. Following ovulation, the follicle becomes what is known as a corpus luteum. If a pregnancy doesn't occur, the corpus luteum usually breaks down and disappears. It may, however, fill with fluid or blood and persist on the ovary. Usually, this cyst is found on only one side and produces no symptoms.
Hemorrhagic cyst: A hemorrhagic cyst is a functional cyst that occurs when bleeding occurs within a cyst. Symptoms of this type of cyst is abdominal pain on one side of the body.
Dermoid cyst: A dermoid cyst is a benign tumor sometimes referred to as mature cystic teratoma. It is an abnormal cyst that usually affects younger women and may grow to 6 inches in diameter. A dermoid cyst can contain other types of body tissues such as fat and occasionally bone, hair, and cartilage.
The ultrasound appearance of this type of cyst can vary because of the spectrum of its contents, but a CT scan and magnetic resonance imaging (MRI) can show the presence of fat and/or dense calcifications. These cysts can become inflamed. They can also cause the ovary to twist on a stalk (a condition known as ovarian torsion), compromising the blood supply and causing severe abdominal pain.
Endometriomas or endometrioid cysts: Endometriomas or endometrioid cysts are a manifestation of the condition known as endometriosis, this type of cyst is formed when endometrial tissue (the lining tissue of the uterus) is present on the ovaries. It affects women during the reproductive years and may cause chronic pelvic pain both associated with, and remote from, menstruation.
Endometriosis is the presence of endometrial glands and tissue outside the uterus. Women with endometriosis may have problems becoming pregnant. Endometrioid cysts, often filled with dark, reddish-brown blood, may range in size from 0.75-8 inches. Due to the color of the old blood frequently found within the cysts, they have been referred to as "chocolate cysts."
Polycystic ovaries: A polycystic ovary is diagnosed based on its enlarged size - usually twice that of normal - with many small cysts underlying the surface of the ovary. This condition can be found in healthy women and in women with hormonal (endocrine) disorders. An ultrasound may be helpful in diagnosing this condition.
Polycystic ovary is different from the polycystic ovarian syndrome (PCOS), which includes other symptoms and physiological abnormalities in addition to the presence of ovarian cysts. Polycystic ovarian syndrome involves metabolic and cardiovascular risks linked to insulin resistance. These risks include impaired glucose tolerance, type 2 diabetes, and high blood pressure.
Polycystic ovarian syndrome is associated with infertility, abnormal bleeding, increased incidences of miscarriage, and pregnancy-related complications. Polycystic ovarian syndrome is extremely common and is thought to occur in 4%-7% of reproductive age women. PCOS also is associated with an increased risk for endometrial cancer. Other tests other than ultrasound are required to diagnose polycystic ovarian syndrome.
Cystadenoma: A cystadenoma is a type of benign tumor that develops from ovarian tissue. They may be filled with a mucous-type fluid material. Cystadenomas can become very large and may measure 12 inches or more in diameter.
Ovarian cancers: Most ovarian cysts are benign (non-cancerous); however, rarely, ovarian cysts may be related to ovarian cancers.