Ovarian Cysts are fluid or semi-solid filled sacs within or on the ovaries. Many women have ovarian cysts without actually knowing it, even though they are quite common. This is because most of them cause no discomfort, and disappear on their own within months without any treatment. Ovarian cysts become a problem if they do not resolve on their own, if they get bigger, or if they rupture.
Ovarian cysts have been classified into two broad types – Functional ovarian cysts and Pathological ovarian cysts, based on the way they are formed.
Functional Ovarian Cysts
The most common type of ovarian cysts are functional cysts, which occur in relation to the menstrual cycle. During the normal menstrual cycle, a cyst (fluid filled sac) which contains the maturing egg appears on the surface of the ovary and continues to increase in size as the egg matures. This cyst is called a follicle. When the egg is fully mature, it is released from the follicle and ovulation is said to have occurred. Sometimes, the follicle does not break open at ovulation but continues to grow, and it forms a type of cyst called a follicular cyst. After the egg has been released, the follicle can remain and continue to grow. This type of cyst is called a corpus luteum cyst.
Pathological Ovarian Cysts
These types of cysts are not formed in relation to the normal menstrual cycle and include the following:
Dermoid cysts are cysts which are formed on the ovary as a result of improper development of immature cells. They usually contain hair, fat, tooth, and other tissues.
Cystadenomas are a type of abnormal growth (tumor) on the ovary which can be fluid filled.
Endometrioma – An endometrioma is a manifestation of endometriosis. When tissue from the endometrial lining is found on the ovaries, it can form a cyst which typically contains a dark brown fluid, and is sometimes called a chocolate cyst.
Polycystic Ovarian Syndrome (PCOS) – As part of this syndrome, most people will have numerous small cysts on the ovaries. Other symptoms of PCOS are irregular periods and an imbalance in the amounts of female hormones in the body.
Most of the time, ovarian cysts go unnoticed because they do not cause any symptoms. They usually go unnoticed or are discovered only when one has a scan for another complaint.
However, it is possible to experience any of the following:
- Pelvic pain – usually a persistent dull ache
- Pelvic pain during intercourse
- Abdominal bloating or swelling
- Painful bowel movement
- Frequent urination, or a feeling that the bladder is not completely emptied after urinating
If the cyst becomes very large, it may exert pressure on other structures – the uterus, bowel, and the bladder, and cause significant pain and discomfort.
A cyst may rupture and this can cause a sudden, intense abdominal pain and internal bleeding.
A large cyst may cause the ovary to twist around itself, causing intense pain and reduced blood supply to the ovary – called ovarian torsion.
Both ovarian torsion and ruptured ovarian cysts are medical emergencies, which must be treated early to reduce the risk of losing the ovary. The management is usually surgical.
A diagnosis of ovarian cysts is usually confirmed by an ultrasound scan, which would show the cysts. A transvaginal scan usually provides a better view, unless the cyst is very large. In order to determine what type of cyst it is and to ensure that it is not cancerous, one might need more advanced types of scanning, like a CT scan or an MRI scan, depending on what is suspected.
Also, a doctor occasionally will request for a blood test for something called CA-125, which is usually elevated when there is ovarian cancer, and helps to rule it out.
The treatment options offered will depend on the age of the woman, the size of the cyst, the type of cyst, and the symptoms being experienced.
Expectant management – If the cyst is not large and there are no symptoms, a woman can be asked to return after a few weeks for a repeat ultrasound to see if it will resolve on its own or worsen.
Surgery – This is the definitive treatment for all types of cysts. The cyst alone can be removed if the ovary is mostly unaffected in a procedure called an ovarian cystectomy. In some cases (if the cyst has resulted in the ovary being damaged), the whole ovary is taken out in a procedure called an oophorectomy.
The surgery is usually performed laparoscopically – 2 or 3 small cuts are made on the abdomen and thin, rod-like instruments attached to a camera are inserted. The doctor then observes the images on a screen and uses the instruments to remove the cyst and repair the ovary, or to even untwist an ovary that has undergone torsion. In most cases the woman is able to go home on the same day. This can be done successfully even in pregnancy.
Ovarian cysts are less common after menopause. However, if this occurs, there is a significant risk of ovarian cancer, and so prompt management is required