Ovarian are small fluid-filled sacs that develop in a woman’s ovaries. Most are harmless, but some may cause problems such as rupturing, bleeding, or pain; and surgery may be required to remove the cyst(s). It is important to understand the function of the ovaries and how these may form.
Women normally have two ovaries that store and release eggs. Each ovary is about the size of a walnut, and one ovary is located on each side of the uterus. One ovary produces one egg each month, and this process starts a woman’s monthlymenstrual cycle. The egg is enclosed in a sac called a follicle. An egg grows inside the ovary until estrogen (a hormone), signals the uterus to prepare itself for the egg. In turn, the lining of the uterus begins to thicken and prepare for implantation of a fertilized egg resulting in pregnancy. This cycle occurs each month and usually ends when the egg is not fertilized. All contents of the uterus are then expelled if the egg is not fertilized. This is called a menstrual period.
In an ultrasound image, ovarian resemble bubbles. The cyst contains only fluid and is surrounded by a very thin wall.
This kind of cyst is also called a functional cyst, or simple cyst. If a follicle fails to rupture and release the egg, the fluid remains and can form a cyst in the ovary. This usually affects one of the ovaries. Small (smaller than one-half inch) may be present in a normal ovary while follicles are being formed.
Ovarian affect women of all ages. The vast majority of ovarian are considered functional (or physiologic). This means they occur normally and are not part of a disease process. Most ovarian are benign, meaning they are not cancerous, and many disappear on their own in a matter of weeks without treatment. While may be found in ovarian cancer, ovarian typically represent a harmless (benign) condition or a normal process. Ovarian occur most often during a woman’s childbearing years.
The most common types of ovarian are the following:
• Follicular cyst: This type of 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 ovary on which the cyst appears. 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 produce no symptoms and disappear by themselves within a few months.
• Corpus luteum cyst: This type of functional ovarian cyst occurs after an egg has been released from a follicle. After this happens, 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: This type of functional cyst occurs when bleeding occurs within a cyst. Symptoms such as abdominal pain on one side of the body may be present with this type of cyst.
• Dermoid cyst: This is a type of 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 growths of body tissues such as fat and occasionally bone, hair, and cartilage.