Complex ovarian cysts

Your ovaries are the two small, almond-shaped organs located on either side of your pelvis which produce the eggs that are released during your monthly menstrual cycle. Small, fluid-filled sacs, or cysts, sometimes develop on the surface of, or within your ovary. Ovarian cysts are usually harmless and will resolve without treatment after a matter of months. Often, a woman does not even know she has a cyst. However, complex ovarian cysts can cause serious health problems, especially if they rupture.

Ovarian cysts form when your normal, monthly cycle of egg growth, development and release goes awry. It is normal for your ovaries to grow cystic structures (known as follicles) each month. These follicles produce the hormones estrogen and progesterone which are needed to stimulate the release of an egg during your menstrual cycle. Sometimes, however, a normal follicle continues to grow and it becomes known as functional ovarian cyst.

There are two types of functional cysts. A follicular cyst begins when the surge of luteinizing hormone (LH) that in a normal ovarian cycle, stimulates the egg to be released, fails to occur. The follicle therefore doesn’t rupture or release its egg, but instead turns into a cyst. Follicular cysts are rarely serious, not usually painful and will often disappear on their own.

When the LH surge does occur and the egg is released, the remaining, ruptured follicle usually starts to secrete large volumes of estrogen and progesterone. Once this occurs, the follicle becomes known as the corpus luteum ("white body"). Sometimes, the opening left in the follicle by the egg becomes sealed off. Fluid then accumulates inside the corpus luteum, forming a cyst. Although this type of cyst often deteriorates on its own, it has the potential to grow, bleed within its capsule and sometimes, twist the ovary. All these outcomes result in several pelvic or abdominal pain.

Complex ovarian cysts occur less commonly, but typically have more serious outcomes. Complex cysts are those that have both solid and liquid components. There are three common types of complex ovarian cysts. Dermoid cysts form from the cells that produce human eggs (ova). These cells are non-differentiated, which means that they have the potential to develop into any tissue in the human body. As a result, dermoid cysts often contain tissues such as hair, skin or teeth. Dermoid cysts are rarely a cancerous cyst, but they can become large and painful and can cause your ovaries to twist, causing pain.

A second type of complex ovarian cysts, known as an endometrioma, typically develops as a result of endometriosis. In endometriosis, uterine cells grow outside the uterus. Uterine tissue therefore has the potential to attach to your ovary and form a growth. The final type of complex ovarian cyst develops from ovarian tissue. These cystadenomas are usually filled with a watery liquid or mucous and have the potential to grow to be very large – up to 12 or more inches in diameter. Such a large cyst will result in your ovary becoming twisted and excruciatingly painful.

Larger complex ovarian cysts will produce symptoms that will quickly become noticed, but which closely resemble other common causes of abdominal and pelvic pain such as endometriosis or ectopic pregnancy. If you have an ovarian cyst, you may experience menstrual irregularities. You may also experience pelvic pain that tends to radiate to your thighs and buttocks. Pelvic pain may also occur during sexual intercourse, or shortly before your period begins or ends. You may notice heaviness in your abdomen, or nausea, vomiting and breast tenderness similar to that which you would experience in early pregnancy. Sudden severe abdominal pain is an indication that you need to seek urgent medical assistance.

To determine whether or not you have an ovarian cyst, your doctor may wish to perform a manual pelvic examination. It is likely that a more sophisticated test, such as a pelvic ultrasound will also be used to support your diagnosis. A pregnancy test will often be carried out, as may a blood test. The pregnancy test is used to rule out an ectopic pregnancy, whilst the blood test will examine the levels of CA 125 antigen, which is produced by cancerous cysts. This antigen is not just produced by cancers, but also in conditions such as endometriosis and pelvic inflammatory disease.

The diagnosis of a complex ovarian cyst should not be taken lightly and any persistent or sudden pain in your abdomen or pelvis warrants thorough medical investigation.