Ovarian cyst

An ovarian cyst is a fluid-filled sac that develops on an ovary. Ovarian cysts are common and many resolve spontaneously. Most cysts are benign but its important to consider the possibility of cancerous change. Most cysts (even large ones) that are benign can be safely treated by laparoscopic (keyhole) surgery.

There are four main types of ovarian cysts:

Functional cysts:

These are the normal cysts that form as part of the process of making and releasing an egg. They are normally less than 3cm and typically do not cause symptoms or need treatment. These cysts can cause pain if they rupture or have bleeding into themselves. Functional cysts are much less common in women using the combined pill for contraception.

Dermoid cysts

These are relatively common cysts that often do not cause symptoms unless they get quite large. They have very typical features on ultrasound and often contain different tissue types eg hair and teeth.

Endometriomas

Women with endometriosis of the ovaries can result in a ‘chocolate’ cyst (so called as the cyst is filled with old blood which looks like melted chocolate).

Other benign cysts form because of production of fluid or mucus within the ovary and almost always need treatment as they tend to grow over time and never spontaneously resolve.

And finally there are malignant (cancerous) cysts.