An Overview of Breast Fibroadenomas

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Breast fibroadenomas are the most common type of noncancerous breast tumor. They're made up of stroma (fibrous connective tissues that support the mammary gland) and adenosis (lobes that have developed hyperplasia—an enlargement due to an increased rate of cellular reproduction). Many women compare them to marbles, as they are firm and able to be moved around by pressing on the skin.

Fibroadenomas can be felt during your monthly breast self-exam and will show up on mammograms and ultrasounds. Women in their 20s or 30s are most likely to develop a breast fibroadenoma, which may grow larger during pregnancy or breastfeeding (lactation).

Quick facts about breast fibroadenomas.
Brianna Gilmartin / Verywell


Typically, the only symptom of a fibroadenoma is a small lump in the breast that you may discover during a self-exam. These lumps feel firm, round, smooth, rubbery, and are movable. Fibroadenomas are so mobile that women sometimes refer to them as “breast mice,” as they tend to run away from your fingers.

The masses may feel tender or painful, especially right before your period, when they may swell due to hormonal changes.

Most fibroadenomas are between 1 and 5 centimeters (cm) in diameter (0.39 inches to nearly 2 inches), but giant fibroadenomas can be the size of a small lemon—about 15 cm (5.9 inches).

Roughly 10% of all fibroadenomas will disappear over time, and 20% will recur. If they don’t disappear, they usually stop growing when they reach 2 or 3 cm.


The exact cause of fibroadenomas is unknown. They seem to be influenced by estrogen because they appear most often in premenopausal or pregnant women, or in women who are postmenopausal and taking hormone replacement therapy (HRT).

Most fibroadenomas change in size during your menstrual cycle, when your hormone levels are changing. Thus, during this period, the same adenoma can become more noticeable or it may shrink to the point where it is not easily palpable.

Risk Factors

Fibroadenomas are most common in women who are between 15 and 30 years old and in pregnant women. Fibroadenomas occur in 10% of all women and in 20% of African-American women specifically.

Once you hit menopause, your risk goes down unless you're using estrogen therapy.


On a mammogram, fibroadenomas appear as round or oval smooth-edged masses. The outline will be clearly defined, not blurry, and will not be invading the adjacent spaces. Sometimes they are accompanied by coarse calcifications. Fibroadenomas can look like cysts or a well-contained tumor.

If you notice a lump during an exam or if an abnormality is seen on mammography, a breast ultrasound is usually the next step. This is especially true if you have dense breast tissue, which can make a lump more difficult to visualize.

On ultrasound, a fibroadenoma will be easier to distinguish from other tissue because of the way it responds to sound waves. It will appear as a dark area with a definite outline. It will look homogeneous, round or oval, and may have smooth-edged bumps.

If ultrasound doesn’t give a definite result, the next study may be magnetic resonance imaging (MRI).


While imaging tests may suggest a fibroadenoma, the conclusive diagnostic test is usually a breast biopsy.

Different types of biopsy procedures include fine-needle biopsy, core-needle biopsy, and open biopsy. Which your healthcare provider opts for will depend on the characteristics of the lump, its location, and other factors.


A breast biopsy only samples one part of a lump and therefore may not be adequate for ruling out cancer when diagnosing a fibroadenoma.

That's because breast lumps, both benign and cancerous, can be made up of different types of cells. In some cases, a breast biopsy has revealed a fibroadenoma, but after removal, a pathologist has discovered cancer cells as well.

In women over age 35, a definitive diagnosis is more important due to an increased risk of breast cancer, so removal of the lump may be recommended.


It's important to distinguish between the two types of fibroadenomas when choosing the best treatment options because of the difference in associated breast cancer risk.

Fibroadenomas are classified as either:

  • Simple: Most fibroadenomas are the simple type; they are more common in younger women. There’s usually just one mass in your breast, with a definite border and very uniform cells. A simple fibroadenoma does not raise your risk for breast cancer.
  • Complex: Complex fibroadenomas are less common and are more common as women age. While they may have a definite border, it's what is inside this kind of fibroadenoma that makes it different. A complex fibroadenoma will not look organized and uniform like a simple one. Even though complex fibroadenomas don't become cancerous, they may contain a collection of small cysts, calcifications, enlarged breast lobules, papillomas and different kinds of hyperplasia. When atypical hyperplasia occurs, it can raise your risk of developing breast cancer.

Aside from fibroadenoma type, other factors may influence treatment choice, such as:

  • Symptoms, especially discomfort and pain
  • Emotional state, such as undue worry about it being cancer

Be open and honest with your healthcare provider about what you're experiencing so it can be considered when weighing treatment options.

In considering all of this, your healthcare provider will recommend one of the following fibroadenoma treatment options.

Watch and Wait

Since fibroadenomas are not always troublesome and sometimes shrink on their own, just keeping an eye on their progress is the least invasive way to handle them.

Laser Ablation

In your surgeon's office, an ultrasound-guided laser device is used to destroy the fibroadenoma, leaving behind only a tiny scar, no sutures, and no change in breast shape. You don't need general anesthesia and it's usually an outpatient procedure, which means no hospital stay.


Cryoablation is a fast, efficient way to freeze a fibroadenoma. In one office visit, the healthcare provider simply freezes the lump so that healthy tissue can take over. This procedure takes less than 30 minutes and results in a tiny scar.

Radiofrequency Ablation (RFA)

This is a way to remove fibroadenomas without resorting to a lumpectomy. Using local anesthesia and ultrasound guidance, a 6- to 8-millimeter (mm) cut is made above the fibroadenoma. Through this cut, a surgical wand is inserted and then tipped by a knife that is heated by radiofrequency current. This helps cut through the breast tissue without causing much bleeding. Once it reaches the target, small wires and robotic arms capture the fibroadenoma and extract it.


Breast biopsy systems can now be used as a fairly non-invasive way to remove fibroadenomas. In less than an hour, and under local anesthesia, a 6-mm (1/4 inch) cut is made over the fibroadenoma. Then, with ultrasound guidance, a Mammotome probe is threaded into the lump, which vacuums out sections of the tissue. Recovery is quick and your scar will be quite small.

High-Frequency Focused Ultrasound (HFU)

This is a relatively new treatment that has been used for fibroadenomas, and sometimes, even for breast cancer. HFU appears to cause the selective destruction of deep tissues without damaging surrounding healthy tissue.


Surgical removal can be done if you're worried about a fibroadenoma. Depending on the relative size of the lump and your breast, a lumpectomy may cause a change in your breast's size or shape. New fibroadenomas may grow in the neighborhood of the first lump, so you should know that surgery is not a guarantee that you'll never have another fibroadenoma. On the other hand, your fibroadenoma can be carefully examined by a pathologist to make sure your diagnosis is correct.

For pain that may be due to a fibroadenoma, over-the-counter pain medications and applied heat are often used.

Complementary and Alternative Medicine (CAM) Concerns

Herbal tonics, teas (e.g., ginger), castor oil, ointments, and homeopathic pills are sometimes touted as effective treatments, but few controlled studies have looked into these remedies.

One example of such a CAM treatment is the supplement blend Fibrosolve, which claims to be a "noninvasive, risk-free treatment option for fibroadenomas." However, there's little-to-no evidence to back up these claims. While many of the ingredients may be generally considered good for you, consider this risk: If a fibroadenoma is hiding breast cancer and you don't have it removed, cancer may remain undetected. By self-treating, you may be risking your health.

Remember that these approaches don't replace the need for proper testing and treatment. Without a biopsy, and possibly removal of the fibroadenoma, there is always a chance that breast cancer could be missed. This is critical, as the disease is most easily treated in its early stages.

A Word From Verywell

While having a biopsy can be unsettling, it may end up being the best way to reduce anxiety about a fibroadenoma. Most breast lumps are not cancerous, and this is the only way to conclusively determine what's causing yours. Keep in mind that there are many types of breast lumps, only one of which is a fibroadenoma. If you detect one, don't hesitate—get it checked out by your healthcare provider.

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5 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.
  1. Ajmal M, Van Fossen K. Breast Fibroadenoma. Treasure Island, FL: StatPearls Publishing. Updated November 11, 2019.

  2. Papathemelis T, Heim S, Lux MP, Erhardt I, Scharl A, Scharl S. Minimally invasive breast fibroadenoma excision using an ultrasound-guided vacuum-assisted biopsy deviceGeburtshilfe Frauenheilkd. 2017;77(2):176-181. doi:10.1055/s-0043-100387

  3. Li P, Xiao-Yin T, Cui D, et al. Evaluation of the safety and efficacy of percutaneous radiofrequency ablation for treating multiple breast fibroadenomaJ Cancer Res Ther. 2016;12(Supplement):C138-C142. doi:10.4103/jcrt.JCRT_966_16

  4. Peek MCL, Ahmed M, Scudder J, et al. High-intensity focused ultrasound in the treatment of breast fibroadenomata (HIFU-F trial)Int J Hyperthermia. 2018;34(7):1002-1009. doi:10.1080/02656736.2017.1373865

  5. Hartmann LC, Sellers TA, Frost MH, et al. Benign breast disease and the risk of breast cancerN Engl J Med. 2005;353(3):229-237. doi:10.1056/NEJMoa044383

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