Ovarian Cyst vs. Ovarian Cancer

Medically Reviewed by Melinda Ratini, MS, DO on July 18, 2022
5 min read

If your OB/GYN tells you that you have ovarian cysts, it might make you worry about ovarian cancer. But even though these two conditions can bring on similar symptoms, they’re very different from each other.

The key thing to know is that ovarian cysts usually aren’t cancerous. Most of the time, they don’t raise your chances of getting ovarian cancer, either.

Ovarian cysts are small, fluid-filled sacs that form on or in an ovary. Ovaries are glands that make eggs and hormones that are involved in menstruation and pregnancy. There’s one ovary on each side of your womb, or uterus.

Ovarian cysts are common in people with regular menstrual cycles. They usually come and go with your cycle, and most don’t cause any symptoms. They’re less likely after menopause.

About 8% of women who haven’t yet gone through menopause will get an ovarian cyst big enough to need treatment.

Ovarian cancer forms when normal cells in one or both ovaries change and grow out of control. These cells can grow into a solid mass called a tumor. When ovarian cancer spreads, new tumors start growing in other areas of your body.  

Most ovarian cancers happen after menopause. Half of all cases of it are diagnosed in those age 63 and up. The disease is rare when you’re younger than 40.

Ovarian cysts often don’t lead to any symptoms. But when they do, they can cause some that are  similar to those of ovarian cancer, like:

  • Belly pain or ache
  • Bloating
  • Pain during sex
  • Unusual changes in your period
  • Peeing often (this is less common with cysts)

Since these can also be signs of other health conditions, talk to your doctor if you have them.

Unusual growth of hair on your face and body is a symptom that’s more likely to happen with ovarian cysts than with ovarian cancer. You might get it if your body starts to make more male hormones called androgens.

Some rare symptoms that are tied more closely to ovarian cysts are sudden, sharp belly pain; fever; and nausea. These signs could mean you have a cyst that has twisted or broken. Call your doctor or 911 right away if you have serious pain on either side of your lower belly that doesn’t go away.

Most ovarian cysts aren’t cancer and don’t increase your risk of cancer in any other way.

But certain types are more likely to be cancerous. They’re called “complex” ovarian cysts. A complex cyst has solid areas, a nodule (bump) on the surface, or several fluid-filled areas.

Simple cysts, on the other hand, aren’t tied to a higher risk of ovarian cancer. In general, they’re simple in shape -- round or oval.

Before menopause, it’s rare for cancer to be the cause of an ovarian cyst. Fewer than 1% of new growths on or near an ovary are linked to ovarian cancer, says UpToDate, an info resource for doctors.

After menopause, it’s somewhat likelier that new growths on or near your ovaries are due to cancer.

The results of an ultrasound imaging test alone can’t tell your doctor for certain whether you have ovarian cancer. But it can help them figure out if you might have it and guide their next steps.

An ultrasound uses soundwaves to make pictures of the inside of your body. One type, called a transvaginal ultrasound, allows your doctor to see your ovaries. When doctors spot an ovarian cyst, they may do a transvaginal ultrasound to check on it.

The test allows your health care team to look at the features of a cyst – including its size and whether it includes solid areas. That helps them determine whether it’s “almost certainly benign” (probably not cancer) or “has a reasonable chance of being malignant” (it might be cancer).

If your doctor decided the cyst is probably not cancerous, you probably won’t need more imaging tests or surgery to remove it, unless it’s painful or is causing other problems.

If they decide the cyst has a chance of being cancerous, you’ll need more tests or surgery. Your doctor may give you a CA 125 blood test if you’ve gone through menopause. This test can’t tell the doctor whether you have ovarian cancer, but can give them a better sense of your risk for the disease.

If your ultrasound and any other tests lead your doctor to suspect that your cyst is cancer, they  can do surgery to remove the ovary your cyst is in or on. That’s the only way to know for sure if you have ovarian cancer. A surgeon can’t find out by removing just the cyst, because cutting into a cancerous cyst could cause the disease to spread.

If you need surgery, your doctor might refer you to a gynecologist who does operations or to a doctor who specializes in diagnosing and treating cancers of the ovaries, vagina, uterus, cervix, and vulva. 

If you have an ovarian cyst, your doctor might recommend one or more of these:

Watchful waiting. Your doctor may suggest this if your cyst doesn’t look cancerous. Watchful waiting means you get an ultrasound every couple months to see if your cyst stays the same size, gets smaller, or goes away on its own. In cases like these, you might not need treatment.

Over-the-counter or prescription pain medicine. Your doctor might recommend this if your cyst brings on painful symptoms.

Birth control pills. These can keep certain types of new cysts from growing.

Surgery. Some of the reasons your doctor may recommend surgery to remove an ovarian cyst are:

  • It’s causing lots of pain or pressure.
  • It may break or twist.
  • It looks like it might be due to endometriosis, and you want it removed so it doesn’t affect your fertility.
  • The cyst is very large.
  • They think it may be cancerous.

If you have ovarian cancer, the main treatment for most types of the disease is surgery. How much and what kind of surgery you need depends on your general health and on how far the cancer has spread.

Your doctor might also recommend another treatment, based on things like the type of ovarian cancer you have and its stage. Some other treatments are:

  • Chemotherapy
  • Radiation
  • Hormone therapy
  • Targeted drugs

Ask your doctor to explain the benefits and risks of each treatment they recommend for you.