Breast Cyst vs. Breast Cancer: What Are the Differences?

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About 1 in 8 women will be diagnosed with breast cancer at some point in their lifetimes, so it is understandable why finding a lump is frightening. While breast lumps are common in women (and possible but less-so in men), most are not cancerous or life-threatening. Breast cysts, or sacs of fluid in the breast tissue, are one of the most common noncancerous breast lumps.

Learn about the differences between breast cancer and breast cysts, their symptoms, causes, treatments, and more.

Female patient receiving breast scan, radiographer looking at medical image of breast on screen

JohnnyGreig / Getty Images

Symptoms

One of the most noticeable symptoms of both breast cancer and a breast cyst is a lump in the breast. However, there are also differences. Breast cancer is more likely to be a very hard lump, and the edges tend to be irregular. A breast cyst, on the other hand, tends to have smooth edges and may feel more like a grape. Cysts can sometimes be hard, too, so a harder lump does not always mean it's cancerous.

Following is a list of similarities and a list of differences between breast cancer symptoms and breast cyst symptoms.

Breast Cyst Symptoms

  • A breast that increases in size, especially before a period
  • Liquid (other than breast milk) leaking from the nipple
  • Lump in the breast, usually soft with smooth edges
  • Pain in the breast close to the cyst
  • Sore breast, especially before a period
  • Symptoms that lessen or go away entirely after a period

Breast Cancer Symptoms

  • Breast swelling
  • Changes in the nipple, such as turning in
  • Dimpling of the skin on the breast
  • Liquid (other than breast milk) coming out of the nipple
  • Lump in the breast or armpit, usually hard and with irregular edges
  • Pain in the breast or nipple
  • Shape or size changes of the breast
  • Skin changes on the breast or nipple, such as redness, dryness, or flaking
  • Swollen lymph nodes near the breast or under the arm

Causes

Some risk factors of breast cancer and breast cysts may be similar, such as women being at an increased risk of both. However, other risk factors and causes vary.

Breast Cyst Causes

Breast cysts can occur when glands in the breast become blocked, or they can grow due to natural, monthly hormone changes, especially before a period. They may also be caused by caffeine, but not enough research is available to confirm this. Cysts in the breast are also more common in women close to menopause, the time when periods have stopped for 12 months in a row, signaling the end of menstrual cycles.

Breast Cancer Causes

The specific causes of breast cancer are not entirely understood. Like other cancers, breast cancer occurs when damaged cells divide and spread uncontrollably, and the body cannot stop them. This is linked to changes in genes (mutations) inherited from parents about 10% of the time.

People at a greater risk of breast cancer are women older than 50 who started menstruating early (before age 12), experienced menopause late (after age 55), or have dense breast tissue (more connective tissue than fatty tissue). Certain lifestyle choices can also increase the risk of breast cancer, such as having excess weight or obesity, drinking alcohol, and not being physically active, among others.

Diagnosis

While over 80% of breast lumps are not cancerous, you should always visit your healthcare provider if you have a breast lump, as a malignant (cancerous) lump can be life-threatening.

Breast cancer and breast cysts are diagnosed with a physical exam and testing; they cannot be diagnosed by touch alone. Because breast cancer and cysts can look similar, tests are designed to differentiate between the two.

Diagnostic testing may include:

  • Aspiration or biopsy: Removes a small piece of the lump and tests it in a lab.
  • Magnetic resonance imaging (MRI): Uses a strong magnetic field and radio waves to scan the breast area and create an image of structures in the breast on a computer.
  • Mammogram: A breast X-ray that is more detailed than a traditional X-ray.
  • Ultrasound: Uses a machine with sound wave technology to create an image on a computer.

Treatment

Getting an accurate diagnosis for a breast lump is extremely important as treatment options vary considerably. For example, breast cysts can be left untreated since they usually are not harmful and go away on their own. Breast cancer, however, can be life-threatening and is usually treated quickly to prevent it from spreading and worsening.

Breast Cyst Treatment

Breast cysts are generally left untreated since they are unlikely to cause harm. However, fluid can be drained if cysts are uncomfortable or painful and can be emptied multiple times if fluid returns.

Breast Cyst Treatment

Breast Cancer Treatment

Breast cancer treatment depends on the stage, whether the cancer has spread, and its specific location within the breast. For example, stage 1 breast cancer that has not spread may only be treated with surgery or with surgery and radiation therapy. 3 or 4 cancer that has spread is often treated with a combination of surgery, radiation, chemotherapy, and/or other systemic therapy.

Breast Cancer Treatment

  • Biological therapy (treatment made with substances from living organisms)
  • Chemotherapy (drug treatment that interferes with normal reproduction and cell division)
  • Hormone therapy (prevents hormones that enable cancer growth from binding to receptors)
  • Immunotherapy (treatments that use the immune system to help fight cancer)
  • Radiation therapy (X-ray treatment)
  • Surgery
  • Other systemic therapy (medicine administered throughout the body - not localized to the cancer site)
  • Targeted medications

Prevention

One of the best ways to prevent breast cancer and care for your breasts is to be aware of how they look and feel and to check routinely for any changes. Other ways to avoid breast cysts and cancer include making healthy lifestyle choices and/or taking medication.

Breast Cyst Prevention

There is limited research about how to prevent breast cysts. Limiting caffeine, including in chocolate, coffee, tea, and other drinks with caffeine, may help. Hormone medications like birth control may also regulate hormones and treat or prevent breast cysts.

Breast Cancer Prevention

While there is no guaranteed way to avoid breast cancer, there are things you can do to make it less likely. For example, a plant-based diet can reduce the risk of developing cancer, including breast cancer.

People with a family history of breast cancer or who are at an increased risk due to genetic mutations can talk with a healthcare provider about genetic testing and prevention options. They may recommend medications or other treatments.

How to Prevent Breast Cancer

Summary

While breast cysts and breast cancer both appear as lumps in the breast, they are two very different conditions. Generally, breast cancer is hard with rough edges, while breast cysts tend to be softer, with smooth edges. See your healthcare provider if you find any breast lumps to determine what it is. While lumps are usually noncancerous, they can be life-threatening, and early diagnosis helps with treatment and outcomes.

Both breast cysts and cancer can be diagnosed with physical exams and testing, such as a mammogram, ultrasound, and aspiration or biopsy. Breast cysts are usually watched but not treated, while breast cancer usually is treated with surgery, radiation, or other options depending on its progression. These conditions can sometimes be prevented with lifestyle choices such as eating a healthy diet, exercising, and getting regular breast screenings.

A Word From Verywell

Finding a lump in the breast can be scary. It is important to remember that most breast lumps do not cause harm, but it is still important to get them checked by a medical professional. If you or someone you know has a breast lump, seek support from a healthcare professional, such as a primary care provider or an obstetrician-gynecologist (ob-gyn).

21 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Ashley Olivine, Ph.D., MPH
Dr. Ashley Olivine is a health psychologist and public health professional with over a decade of experience serving clients in the clinical setting and private practice. She has also researched a wide variety psychology and public health topics such as the management of health risk factors, chronic illness, maternal and child wellbeing, and child development.