December 13, 2023

Is It a Cyst or Something More Serious?

Can’t identify that lump in your breast? Let us provide some acystance.

This piece originally appeared on

If you’ve ever felt a lump in your breast, you know it can be a pretty terrifying experience. But not all lumps mean cancer: You might just have a cyst.

The word “cyst” might make you think of acne, but the truth is that cysts can occur in your kidneys, liver, breasts, and elsewhere in the body. In fact, breast cysts are common, and nothing to be embarrassed about. So what are cysts, and why do we get them?

To educate the masses about these little masses, we asked an expert — Jennifer Racz, MD,  Director of Medical Affairs for Oncology at Exact Sciences. Here she gives us the gist on cysts, and explains what to do if you think you’ve got one.

What is a breast cyst?

Our bodies are made up mostly of water, and a cyst is no different: “A breast cyst is a fluid-filled sac inside the breast caused by fluid accumulation inside the glands in the breast,” explains Dr. Racz.  Finding a cyst is pretty common — 25 percent of masses in women are breast cysts.  Breast cysts can be found in one or both breasts.

This sounds simple enough, but not all cysts are created equal. There are three types: simple, complicated, or complex. These categories are determined by the shape and appearance of the cyst on an ultrasound. “A simple cyst has smooth borders,” says Dr. Racz. “It’s often described as having the consistency of a grape or a water-filled balloon, but sometimes a breast cyst feels firm.” Complicated or complex cysts won’t have these well-defined borders: “These may have thicker walls, will be uneven in shape, and have a different appearance on ultrasound,” says Dr. Racz. “Your physician will be able to tell what type of cyst you have on an ultrasound, to determine if any intervention is necessary.”

Can cysts cause cancer?

In most cases, the answer is no. Simple cysts are almost always benign, and complex or complicated cysts are usually benign as well — but not always. “In rare cases, a complex or complicated cyst can harbor malignant cells,” says Dr. Racz. “These require aspiration (draining some fluid from the cyst using a needle under ultrasound guidance), so the physician can send the fluid for culture and pathology. Depending on the result, your doctor may then recommend a biopsy.” The good news, says Dr. Racz, is that cancerous cysts are rare: “The risk of malignancy with a complex cyst is low.”

Unlike breast cancer, there are no clear biological determinants for cyst development: It’s unlikely that there’s a genetic component, and breast density doesn’t mean you’re more likely to develop cysts. But if you do get a cyst, prepare to get another one — about 50 percent of women who develop one cyst will get more over their lifetime. But even if you experience cysts frequently, that doesn’t mean you’re more likely to develop breast cancer.

Can you feel the difference between a tumor and a cyst in the breast?

No, but having breast cysts may make it harder to find new breast lumps or other changes that might need evaluation by your doctor.  Common signs and symptoms of a breast cyst include breast pain or tenderness, an increase in size just before your period, a decrease in size after your period, or nipple discharge that is clear, yellow, brown, or straw-colored. Most importantly, your breasts may change with your period, so becoming familiar with how your breasts feel is important to know if something is changing.  “The bottom line is that you can’t definitively distinguish between a cyst and a tumor during a self breast exam, so if you feel anything out of the ordinary, you need to consult your physician,” says Dr. Racz. If you find a mass that has an irregular border, is painless, and doesn’t seem to change in size with hormonal fluctuations, you should get it checked out as soon as possible.

If you find any kind of lump in your breast, you’ll need to undergo imaging so your physician can see what’s happening. The type of imaging your doctor will recommend depends on several factors, including your age, the differential diagnosis (potential causes), and your breast density. “In some cases, the only test required is an ultrasound, whereas in other cases, additional imaging with a mammogram or MRI may be necessary.” Dr. Racz explains.

At what age are you most likely to develop a breast cyst?

There’s no definitive answer to this question, as breast cysts can be found in women of any age.  However, they seem to be most common in women before menopause between the ages of 35 and 50 and are influenced by the presence of hormones or hormonal fluctuations.  Although they are most common in this age range, they can also be found in postmenopausal women who take hormonal therapy.  Not every woman will develop a cyst during their lifetime — which is just one more thing about our bodies that varies from woman to woman.

What is breast cyst treatment?

In almost all cases, these cysts will go away on their own. “Over time, the fluid in a cyst will get absorbed back into your body, and if it’s a small volume, you likely won’t even notice it,” says Dr. Racz. This means that a cyst could rupture in your breast without you even noticing — one day, it’ll just be gone.

Cysts get smaller with time — 70 percent resolve on their own within five years. And although you may experience a bit of nipple discharge or breast pain/discomfort, breast cysts usually aren’t associated with any symptoms. But if a cyst is causing you pain or discomfort, Dr. Racz says there are some options: “If a patient has a really large cyst and it’s causing pain in the breast, we can aspirate it to remove the fluid, which will relieve the distension and discomfort.” The bottom line? If you’ve got a simple cyst, the best course of action is usually just to leave it alone.

The information provided is not clinical, diagnostic, or treatment advice. You should consult with a qualified healthcare provider about any questions you may have regarding a medical condition or treatment. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.