Imaging Tests for Ovarian Cysts

When you need an ultrasound—and when you don’t

Most ovarian cysts are small sacs, filled with fluid, on your ovaries. These are called “simple” ovarian cysts.

If your healthcare provider finds an unexpected cyst or enlarged ovary during a pelvic exam, you should have a vaginal ultrasound to assess for cancer. However, many women have follow-up ultrasound exams to make sure that cancer doesn’t grow later. Most of the time those extra exams are not needed. Here’s why:

Most ovarian cysts are low-risk and can be ignored.

A simple ovarian cyst often forms as part of the normal menstrual cycle. About one in five women who are past menopause also get them. These cysts are small and usually do not cause symptoms. And they usually do not turn out to be cancerous in women of any age.

Research has shown that if the cyst does not show signs of cancer, cancer is not likely to grow later. For that reason, it is safe to ignore the cyst after the first vaginal ultrasound, as long as it does not start to cause symptoms, such as pelvic pain.

Ultrasound is safe, but follow-up can have risks.

During an ultrasound, a slender instrument is placed inside the vagina and sound waves are used to create pictures. An ultrasound exam does not expose you to radiation. And it is not costly. So repeating it may seem harmless.

But being called back a few weeks or months after the first ultrasound to check the cyst again may cause anxiety. And by then you may be in a new menstrual cycle. The old cyst may have gone away on its own. But a new cyst may have formed, which can lead to a follow-up ultrasound on the new one.

These rounds of ultrasound can also lead to unnecessary surgery to remove a cyst or ovary. For instance, some doctors take out cysts that do not appear to go away or that look bigger on follow-up tests, even though they would almost never become cancerous. The risks of this surgery include pain, bleeding, and infection.

The tests can be a waste of money.

If you do not have health insurance, a vaginal ultrasound can be expensive, and an operation to remove an ovarian cyst can cost thousands of dollars. And any money spent on unnecessary tests and procedures is money wasted.

So when should you have a follow-up ultrasound test?

You may need a follow-up ultrasound test, and sometimes surgery, if the first ultrasound shows that you have a large cyst or a cyst that may be cancerous or could develop into cancer. If a cyst has the appearance of cancer, it should be removed right away. A surgeon who specializes in treating ovarian cancer should do the surgery. That type of surgeon is called a gynecologic oncologist.

This report is for you to use when talking with your healthcare provider. It is not a substitute for medical advice and treatment. Use of this report is at your own risk.

© 2016 Consumer Reports. Developed in cooperation with the American College of Radiology.