Ovarian cysts: types, symptoms and treatment
Ovarian cysts are fluid-filled sacs that develop on the ovary. Ovarian cysts are common and can occur in women of all ages. Most ovarian cysts present with little or no discomfort, are harmless and resolve spontaneously within a few months.
By contrast, ovarian lesions that are solid (not fluid filled) cannot be called cysts.
In premenopausal women cysts are common and develop under the influence of sex hormones during a women’s normal menstrual cycle. Each month, the ovary grows tiny sacs (follicles) that hold the eggs. A functional cyst develops when the ovary fails to release an egg or when a follicle in the ovary continues to grow after an egg has been released. These cysts usually resolve without treatment.
Non-functional cysts are less common and are cysts that grow without the influence of hormones. The exact causes are unknown.
- Dermoid cysts: Sac-like benign growths on the ovaries that can contain hair, fat, teeth, bone and other tissue. Growing teeth in the ovaries sounds strange but dermoid cysts develop from ‘totipotential germ cells, sometimes referred to as ‘master cells’ because of their ability to mature into any type of tissue. These cells can become over stimulated in women during their reproductive years (mainly 30s).
- Cystadenomas: Benign growths that can develop on the outer surface of the ovaries. They can be filled with a transparent, watery fluid or can be filled with mucus.
- Endometriomas: Tissues that normally grow inside the uterus can develop outside the uterus and attach to the ovaries. Endometriomas occur due to a condition called endometriosis.
- Polycystic ovarian syndrome (PCOS) stands for ovaries with innumerable tiny ovarian cysts. These cysts do not normally need to be removed, but women with PCOS may need treatment for other PCOS problems.
Symptoms can differ in women. Depending on its size, some cysts cause pain and in functional cysts the pain will ease soon. Large cysts can cause persisting pain and discomfort, pelvic pressure, bloating or fullness and also urinary frequency. Irregular menstrual periods are not usually related to an ovarian cyst.
Endometriomas develop mostly in women below the age of 50 years and may be associated with painful periods.
Ovarian cysts typically are diagnosed during a pelvic examination or a pelvic ultrasound. The ultrasound will help to assess its nature.
Is the cyst cancerous?
Overall, less than 1% of new growths on or near the ovary are related to ovarian cancer.
There is no 100% reliable test if an ovarian cyst is harmless or ovarian cancer. However, a few tests can be done to assess the risk of a cyst being malignant (cancer) or benign.
- Patient age: Ovarian cancer mainly affects women after the age of 50 years.
- The ultrasound will show if the ovarian cyst is purely cystic (a simple cyst) or if it contains some solid elements. The risk of a simple ovarian cyst to be cancerous is only 1% or less. Most patients would be happy to be reassured.
- Tumour marker blood tests: There are some blood tests your doctor can request and the result of the blood test will help professionals to estimate the risk of cancer.
- CA125 is the most widely used and most useful blood tumour marker.
- CA19.9 is another blood tumour marker that would detect mucinous tumours.
- HE4 is a marker that is useful to detect endometriosis and endometriomas.
- In young women, a totally different set of tumour marker needs to be taken to assess the risk of non-epithelial ovarian cancer.
In summary, a women less than 50 years of age, with a simple ovarian cyst (no solid elements) and a low CA125 blood test has a very low risk that her ovarian cyst could be malignant.
Complications of ovarian cysts
Ovarian cysts, such as dermoids in particular can grow large causing ovarian torsion. This is rare but occurs when a large cyst causes an ovary to twist around its own blood supply or move from its original position. Ovarian torsion can also decrease or cut off the blood flow to the ovaries, resulting in severe acute pain. Ruptured cysts can cause intense pain and internal bleeding. Ovarian torsion and ruptured cysts require immediate treatment.
Ovarian cysts in premenopausal women typically resolve themselves. In postmenopausal women cysts are often non-functional. In postmenopausal women if a cyst grows or changes in appearance, then surgery to remove the cyst may be recommended to explore and exclude ovarian cancer.
In young women, the surgery may involve removing only the cyst. If the cyst is small and appears non-cancerous the cyst alone is removed laparoscopically through several small incisions near the navel. If the cyst is large or appears suspicious for cancer, it may be necessary to have an open incision through the abdomen. Having one ovary removed will not cause women to go through menopause and does not cause infertility.
In menopausal women, I recommend removing the entire ovary (and not simply the cyst). In these women, it is also important to remove the ovarian cyst without spilling any cyst fluid. Should the cyst be cancerous, I would like to see the content of the cyst contained and not disseminated in the abdominal cavity. The majority of these procedures can be done laparoscopically with a hospital stay of 1 night.
For suspicious cysts and ovarian masses, I recommend a frozen section examination. This means that I invite a pathologist into the operating theatre who will snap freeze the tissue and examine whether there is cancer while the patient is still asleep.