How do surgeons determine if a cyst is benign or malignant and requires removal?

From a gynaecologist's perspective, ovarian cysts in women are fluid-filled sacs that develop in one of the ovaries. There are many types of ovarian cysts and in most cases, the cysts are painless and cause no symptoms.

Most ovarian cysts are benign or functional and go away with time. However, some cysts do cause symptoms such as pain and bloating and may require treatment. An ultrasound scan of the ovaries can help determine the type, size and location of the ovarian cyst.

According to the International Ovarian Tumour Analysis (IOTA) group ultrasound rules for ovarian masses, if an ovarian cyst has at least one of these features and no benign features, the chance of malignancy is high:

1. irregular solid tumour
2. irregular multilocular-solid mass >10 cm in size
3. ≥4 papillary structures
4. presence of abdominal fluid (ascites)
5. high Doppler signal (the cyst is highly vascular)

In this instance, further workup with advanced imaging and surgical removal would be advised. In some instances, a pre-operative biopsy of the ovarian cyst can be performed to establish the diagnosis.

A consult with a gynaecologist experienced with managing ovarian cancer is advised.

If you are referring to skin cysts, these are generally benign but has the risk of increasing in size or becoming inflamed and infected over time. An experienced doctor can usually diagnose a cyst from its clinical appearance.

Common ways of removing cysts are:

• Drainage of cyst
• Injecting of medicine into the cyst
• Removal by minor surgery
• Removal by laser

Occasionally, an ultrasound scan of the lump may be requested prior to surgery. For patients who opt for cyst removal, we will routinely send it off for analysis at a specialised laboratory to ensure the lesion removed is harmless and not cancerous. This is important in order to determine if the cyst is benign or malignant.

Most cysts are actually benign. Malignant cysts refer to cysts that harbour cancer or those with a potential to develop into cancer.

In determining whether or not they are malignant, the cysts are monitored for changes in size and consistency with regular ultrasounds. In some cases, you might also need to get an MRI.

The surgeon would choose the necessary treatment based on symptoms such as:

• Pain
• Enlargement of the cyst size
• Presence of solid tissue within the cyst

Treatment does not necesarry mean removal. Depending on your condition, doctors might also recommend aspiration of the cyst fluid for testing.