An ovarian cyst is just a fluid-filled sac in the ovary. They can vary in size and contain liquid that is thin and watery, or thicker and paste-like. Cysts are very common in the ovary as a result of the ovulation cycle. Even normally, the follicle ( in which the egg grows) contains fluid.  If the follicle doesn’t rupture at the time of ovulation ( when the egg is released) , the follicle gets bigger as it swells with fluid. This follicular cyst is also called a functional cyst, because it is a result of ovarian function. The other type of functional cyst is a corpus luteum cyst which develops when the corpus luteum  fills with fluid or blood. When bleeding occurs within a functional cyst, this is called a hemorrhagic cyst.

Many women with endometriosis also have ovarian cysts. These are called chocolate cysts, because of the colour of their contents ( old dark blood). Cysts are also found in women with PCOD.

Occasionally a dermoid cyst (sometimes called a benign mature cystic teratoma) may develop  This type of cyst can contain a range of tissues, such as hair, skin or teeth, because it forms from cells that make eggs in the ovaries. Dermoid cysts are more common in younger women and may need to be surgically removed.

A cystadenoma is a cyst that develops from the cells that cover the outer part of the ovary. There are different types – some are filled with a watery liquid ( serous cystadenoma) , and others with a thicker, mucous substance ( mucinous cystadenoma) . They’re not normally cancerous, but may need to be surgically removed.
 

Most ovarian cysts do not cause symptoms, and are usually first noted on ultrasound scanning. Partly because of the quality and resolution of the new ultrasound scanners, even small cysts ( which are of no clinical importance) are diagnosed and reported routinely. Many patients then start worrying about the effect of these cysts on their fertility. Unfortunately , sometimes instead of reassuring them, their doctors advise them to get these cysts removed. This often causes more harm than good !
 

Most cysts do not cause symptoms, and are best left alone. Occasionally, some cysts may cause irregular menstrual bleeding, if the cyst is hormonally active; or pelvic pain . While often the cyst is not the cause of the pain, once the patient knows she has a cyst, everytime she perceives pain, she feels it is the cyst which is causing it ! Cysts can cause pain only if:
·       They are large and exert direct pressure on the ovaries and surrounding structures. This causes chronic pelvic fullness or a dull ache.
·       Bleeding from a cyst into and around the ovary. This causes more intense, sharp pain.

In rare cases, an ovarian cyst may become twisted and cut off its own blood supply. It is called torsion This can cause severe abdominal pain, vomiting, and fever. This requires immediate medical attention. In other cases, the cyst may burst, causing sudden severe pain in the lower abdomen. The pain you feel depends on what the cyst contained, whether it is infected and whether there is any bleeding. This usually needs treatment in hospital as well.

The key tool for making  a diagnosis of an ovarian cyst is an ultrasound scan. If the cyst is very large, an  abdominal scan will need to be done to measure its size. Otherwise, the location and size of a cyst is best determined by a vaginal ultrasound scan. Ultrasound scanning allows us to assess the contents of the cyst; and cysts are classified into 3 types, depending upon their ultrasound appearance:

1.      cystic . This is the commonest type. This cyst has a wall and contains only fluid.

2.      solid. This type has multiple echoes within it, because it is full of solid tissue.

3.      complex. This has a combination of both fluid and solid tissue within it. Many of these cysts have walls of tissue within them – these are called septae.

Simple cysts are usually functional cysts, and will resolve on their own. Complex cysts are more worrisome, and may need additional testing , including: MRI scanning; or a blood test to measure the level of  CA-125. If there is a tumour, the level of this protein is usually higher than normal.

Treatment of Ovarian Cyst

Wait and See – This approach involves waiting a few months to see if the cyst goes away on its own. In some cases, observation may be all that’s necessary. This is common in pre-menopausal women who have a small, functional cyst. You’ll need to have another ultrasound scan after a month or so to check on the cyst, but most disappear after a few weeks without treatment.
 

Birth Control Pills – If you have a functional cyst, your doctor may prescribe birth control pills to help make it smaller. If you get ovarian cyst often, birth control pills decrease the chance of new ones forming.
 

A simple cyst can also be treated by vaginal ultrasound guided aspiration. This will allow the doctor to empty its fluid contents, and maybe useful as a temporizing and diagnostic measure.

Laparoscopic Surgery – Pelvic laparoscopy may be recommended to remove a cyst if it:

·       Grows larger or reaches a size greater than 5 cm

·       Has some solid material in it

·       Causes persistent or worsening symptoms

·       Lasts longer than two or three menstrual cycles

If the cyst is not cancerous, often just the cyst can be removed. However, in some cases, your whole ovary may need to be removed.

Most cysts can be removed with laparoscopic surgery by a skilled surgeon, irrespective of their size. ( No matter the size of the cyst, it can be decompressed laparoscopically, causing it to collapse, so that the cyst wall can be removed through a keyhole incision, saving the patient unnecessary major surgery. ) This is usually the preferred mode of treatment in infertile women, because it allows the doctor to save ( conserve) the normal ovarian tissue, thus preserving normal ovarian function.

Rarely, laparotomy ( open surgery) may be needed if the cyst is solid or complex; and if the doctor suspects a malignancy.

Ironically, in many infertile women, the major risk posed by ovarian cysts is not because of the cyst itself, but because of the overenthusiastic zeal of a misguided surgeon, who wants to remove the cyst. This is often much more dangerous, because many trigger-happy surgeons remove the entire ovary, thus compromising ovarian function; and because the surgery can result in scarring ( adhesions) which will then impair tubal function.