Ovarian Cysts

Most ovarian cysts are normal functional cysts on the ovary. A small proportion of ovarian cysts can enlarge, bleed, cause pain and/or become cancerous.

To understand ovarian cysts, we need to know how the normal ovary functions during a menstrual cycle.

The ovaries are part of the female reproductive system that are regulated by the hormones estrogen and progesterone. Ovulation occurs every month, when the ovary releases an egg under the influence of the hormones. The egg grows inside a tiny fluid-filled sac called a follicle. The follicle breaks open to release the egg as it matures.

There are various types of ovarian cysts as described below:

Follicle Cysts:

When the follicle fails to release the egg, it continues to grow to form a follicular cyst. Often, these cysts do not cause any symptoms and resolve spontaneously over the next 2-3 menstrual cycles. Cysts that do not resolve or become enlarged beyond 4-5 cm are at risk of rupture, torsion and may require to be surgically removed.

Ovarian cysts are common in women with regular periods. It is rare to develop ovarian cyst after menopause and large cyst in this age group should always be investigated.

Corpus Luteum Cysts:

When an egg is released, the empty follicle forms a corpus Luteum. The corpus luteum is important as it produces hormones (progesterone) to support a pregnancy, should it occur. Rarely, the corpus luteum forms to become a cyst with fluid & blood inside. Most corpus luteum cysts also resolve in few weeks. However, they can grow to large sizes and may bleed or twist the ovary and cause pain.

Dermoid Cyst:

A dermoid cyst is an abnormal ovarian cyst that develops from pluri-potent cells (which are present from birth). They grow very slowly and contain mature tissue (hair, fat, cartilage and other tissues), and are almost always benign (non-cancerous). Rarely, they can be found on both ovaries. They usually do not cause symptoms, but can reach become very large in size. They are at risk of torsion and rupture. Dermoid ovarian cysts that are large or cause complications require surgical removal by either laparoscopy (key hole) or laparotomy (open surgery). Most dermoid cysts can be managed safely and successfully by performing a laparoscopy.


These are non-cancerous ovarian growths that can develop on the outer surface of ovaries.


Endometriomas are ovarian cysts that are lined by endometriotic implants. These ovarian cysts are filled with old blood that resembles dark brown fluid and are sometimes called “chocolate cysts”. This is a severe form of endometriosis, and surgical success depends on the experience of the gynaecological surgeon. Read more about endometriomas in our section on Endometriosis.

Polycystic Ovary Syndrome (PCOS):

Multiple small immature follicles on an ovary cause the ovary to swell up. PCOS can cause irregular menstrual cycles, infertility and symptoms of increased male hormones (acne, hirsutism). The management of PCOS is mostly medical.

Malignant (cancerous) ovarian cysts are rare.

They are more common in older women and hence need to be evaluated by medical doctors as soon as possible. Women who are past menopause and develop ovarian cysts have a higher risk for ovarian cancer.


Most ovarian cysts are small and don’t cause symptoms. However, the cysts that have enlarged can cause symptoms of pressure, bloating, swelling, or pain in the lower abdomen. This pain may be sharp or dull and may be constant in nature. A cyst rupture or a twisting of the ovarian cyst pedicle can cause severe pain.

Other possible presentations may be:

• Pelvic pain
• Pain during sex
• Pain during your period
• Backache
• Unexplained weight gain or loss
• Needing to urinate more often
• Problems emptying the bladder or bowel completely

If you have above symptoms, speak to you GP. Your GP will be able to establish if you require a specialist referral. Following a pelvic exam, your doctor may recommend a pelvic ultrasound. A pelvic ultrasound is a non-invasive way to get more information on the nature of the ovarian cyst. Typically, important features on pelvic ultrasound include the size, shape, content, presence or absence of solid components, vascularity and the status of the other ovary.

Additionally, blood tests may be recommended to note hormonal levels and tumour markers (eg. CA-125) which may be increased in some forms of ovarian cancer.


If an ovarian cyst persists or continues to enlarge, it requires treatment. The available methods of treatment are:

Oral Contraceptive Pills (OCP) – Birth Control Pills
This may be beneficial if you suffer from recurrent ovarian cysts. OCP’s inhibit ovulation and thereby prevent the development of new cysts. OCP’s can also reduce your risk of ovarian cancer. This is, however, not useful if the cyst is already present and enlarged.

If primary investigations help exclude a malignancy, Laparoscopic Ovarian Cystectomy (removal of the cyst from the ovary) may be suggested. This is easier and safer in the hands of an gynaecologist who is an expert in laparoscopy.

Laparotomy (open surgery)
If you have a very large cyst, which cannot be safely removed via laparoscopy or if the suspicion of ovarian cancer is very high, a laparotomy is considered. A frozen section (immediate biopsy) is done, and if the cyst is found to be cancerous, a hysterectomy with removal of your ovaries can be performed.