Demystifying ovarian cysts

BY Dr Brigid Monda

During every normal menstrual cycle, a woman’s ovaries grow tiny cysts called ovarian follicles, little ‘chemical factories’ producing the hormones oestrogen and progesterone that regulate the menstrual cycle.

Each follicle also contains an egg which when mature breaks out of the follicle (ovulation) and begins its journey through the fallopian tube where a sperm reaching it will fertilise it. The follicle left behind dissolves.

Sometimes, the ovaries may form a different type of cyst. The commonest are the functional or follicular cysts which form in the first two weeks of the cycle before ovulation and corpus luteam cysts, which may form after ovulation.

Follicular cyst will form if a follicle just keeps growing without breaking open to release the egg and because ovulation fails to occur, the rest of the cycle becomes irregular.

It causes pain on the side of the ovary on which the cyst is if it ruptures.

A corpus luteum cyst is less common and forms if the follicle left behind after ovulation doesn’t dissolve, instead sealing off and causing fluid building up inside it.

It grows larger than follicular cysts, can twist the ovary or fill up with blood and rupture, causing bleeding and sudden, sharp pain.

It can also cause missed periods. Both follicular and corpus luteum cysts are entirely filled with fluid and so are called ‘simple cysts’. They are not cancerous and usually disappear within three months.

Other types of ovarian cysts are called ‘complex cysts’. Thankfully, most of these cysts are harmless. For example:

Endometriomas: Also called ‘chocolate cysts’ because of their appearance, they develop in women who have endometriosis which involves the ovaries.

Endometriosis occurs when the lining of the womb grows outside the uterus and because it responds to hormones during the menstrual cycle just as it normally would if it were in the uterus, it also bleeds during every period, filling the affected ovary with dark, reddish-brown blood.

Cystadenomas: Grow from cells on the outer surface of the ovary and are filled with a thick sticky ‘gel’, becoming quite large — up to 12 inches or more.

Dermoid cysts: May contain hair, skin or teeth. Are rarely cancerous, but can also become large and cause painful twisting of the ovary.

Many ovarian cysts cause no symptoms. Others cause heaviness and a constant dull ache in the lower back and thighs, frequent urination, painful intercourse or irregular, unusually painful menstrual periods.

Once a cyst is found, a pregnancy test is done as well as an ultrasound to show the cyst’s shape, size and location, whether it’s fluid-filled, solid, or mixed.

Your doctor may also do hormone levels and a blood test to measure CA-125 whose levels are high if a woman has ovarian cancer.

Treatment of cysts

Treatment depends on the size and type of cyst, its symptoms, the woman’s age and future pregnancy plans.

A cyst in a girl before she’s begun menstruation and in a postmenopausal woman is cause for alarm because these are often cancerous.

You can wait two or three months then repeat the scan to see if the cyst has disappeared, persisted or increased in size. If the cyst doesn’t go away after several menstrual periods or gets larger, you’ll need it removed.

If the woman doesn’t want to wait, she can take the contraceptive Pill which should make the cysts disappear. If the cyst is cancerous or won’t go away with the Pill, it will have to be removed through surgery. Your doctor will want to remove it and send the tissue to the laboratory for tests to confirm if it is cancerous or not.