Medically Reviewed By William C. Lloyd III, MD, FACS
Was this helpful?

What is a fibroadenoma?

A fibroadenoma is a benign, or noncancerous, tumor of the breast. Female breasts are made up of three main types of tissues: glandular tissue (milk-producing glands), ductal tissue (ducts that carry milk from the glands to the nipple), and stroma (a combination of fatty tissue and fibrous or connective tissue). Fibroadenomas involve both fibrous and glandular tissues in the breast. They are the most common form of benign breast tumors.

Fibroadenomas commonly occur in women during their reproductive years, particularly during their twenties and thirties. The cause of these tumors is not known. However, genetics is not likely to play a role in the development of fibroadenomas. Women with dark skin tend to develop fibroadenomas more often and at an earlier age than light-skinned women. Similarly, women of higher socioeconomic status tend to develop fibroadenomas more frequently.

Fibroadenomas usually appear in one breast as single lumps that are smooth, rubbery, painless, and easily movable. However, approximately 10 to 15% of women will have multiple lumps that can occur in both breasts (Source: NIH).

Hormonal changes can cause fibroadenomas to grow in size. Hormonal changes occur at the onset of puberty and during menstrual cycles, pregnancy, and breastfeeding. The decline in hormone production during perimenopause and menopause can cause fibroadenomas to shrink unless you use hormone medications.

If you have a breast lump or lumps, you will need to have a biopsy performed to properly diagnose a fibroadenoma and to rule out more serious conditions, such as breast cancer. The treatment of fibroadenomas can vary depending on the size of the tumor, whether it is causing physical deformity of the breast, patient preference, and other factors.

Fibroadenomas are usually benign tumors of the breast and do not pose an immediate medical threat. However, you should consult your healthcare provider about any breast lump for proper evaluation and to rule out other serious conditions, such as breast cancer. Seek prompt medical care if you find a breast lump or have a fibroadenoma that grows larger or changes in any way.

What are the symptoms of a fibroadenoma?

Fibroadenomas usually occur in one breast as a single lump. However, 10 to 15% of women may have multiple tumors that can affect both breasts. Fibroadenomas are usually benign, meaning they are not cancerous, but if they are large, they can cause physical deformities and changes in your breast. Fibroadenomas usually have the following characteristics:

  • Easily movable and not fixed in place under the skin

  • Firm

  • Painless

  • Rubbery

  • Smooth

Because other breast conditions, such as breast cancer, can have similar symptoms, a biopsy is needed to properly diagnose a fibroadenoma.
Fibroadenomas are stimulated by the female sex hormones, estrogen and progesterone. As such, they may grow larger during times of hormonal change, such as the onset of puberty and during menstruation, pregnancy and breastfeeding. Conversely, fibroadenomas tend to shrink in size when women enter perimenopause and menopause unless they use hormone replacement therapy.

Symptoms that might indicate a serious condition

In most cases, fibroadenomas are benign breast tumors and are not a serious medical condition. However, any breast lump should be properly evaluated by your healthcare provider to rule out serious conditions. Rarely, fibroadenomas can become cancerous. Seek prompt medical care if you, or someone you are with, have a breast lump or a diagnosed fibroadenoma that grows larger or changes in any way.

What causes a fibroadenoma?

The cause of fibroadenomas is not known. The incidence of fibroadenoma tends to be higher in dark-skinned women and women of higher socioeconomic status. However, there does not appear to be a genetic link or a link with the age of menarche (the beginning of menstruation) or use of oral contraceptives.

What are the risk factors for a fibroadenoma?

A number of factors are thought to increase your chances of developing a fibroadenoma. These risk factors include:

  • Dark-skinned race

  • High socioeconomic status

  • Low body mass index (BMI)

  • No or low number of full-term pregnancies

Reducing your risk of a fibroadenoma

There are no specific ways to reduce your risk of developing a fibroadenoma. However, all women should examine their breasts monthly and have regularly scheduled clinical breast exams and other screenings as recommended by their healthcare providers.

How is a fibroadenoma treated?

A fibroadenoma is diagnosed with a biopsy to rule out more serious conditions, including breast cancer. Once the diagnosis of fibroadenoma is confirmed, you and your healthcare provider can decide on the best course of treatment for you. Small fibroadenomas may go away or regress by themselves. In some cases, your healthcare provider may recommend leaving the lump in place and checking it on a regular basis. This is called observation and is most often recommended for small tumors that can be monitored and are not causing any physical deformities or anxiety.

However, your healthcare provider may recommend removing a fibroadenoma if it is large, the biopsy results are not normal, or it is causing physical deformities or anxiety. Most likely, a breast surgeon will be involved in your decision to remove a fibroadenoma. There are a variety of techniques your surgeon can use to remove a fibroadenoma, including:

  • Cryoablation (destroying the lump by freezing it rather than removing it)

  • Percutaneous excision (removing the tumor with a needle through the skin)

  • Surgical excision, or cutting out the tumor

Each of these procedures has risks and benefits. Your healthcare provider is best able to guide your treatment decision based on your specific circumstances.

What are the potential complications of a fibroadenoma?

Fibroadenomas that are not removed should be checked regularly, based on recommendations from your healthcare provider. Lumps may need to be removed at a later time if they grow, change in any way, or do not go away. In very rare cases, fibroadenomas may become cancerous and require further treatment.

Women who have had a fibroadenoma are at a slightly increased risk for developing breast cancer at some point in their life, especially if there is a family history for breast cancer. Therefore, it is important to have any lumps that are not removed checked on a regular basis. All women should perform breast self-exams on a monthly basis and schedule clinical breast exams and other screenings as recommended by their healthcare provider.

Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 19
View All Women's Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Fibroadenoma - breast.  MedlinePlus, U.S. National Library of Medicine.
  2. Greenberg R, Skornick Y, Kaplan O. Management of breast fibroadenomas. J Gen Intern Med. 1998;13(9):640-645.
  3. What is Breast Cancer? American Cancer Society.
  4. Breast diseases, 4th ed, Harris, JR, et al (Eds), Lippincott, Philadelphia 2010