Causes

Fibroadenoma is the most common benign tumor of the breast and the most common breast tumor in women under age 30.

A fibroadenoma is made up of breast gland tissue and tissue that helps support the breast gland tissue.

Black women tend to develop fibroadenomas more often and at an earlier age than white women. The cause of fibroadenomas is not known.

Symptoms

Fibroadenomas are usually single lumps, but about 10 - 15% of women have several lumps that may affect both breasts.

Lumps may be:

• Easily moveable under the skin
• Firm
• Painless
• Rubbery

They have smooth, well-defined borders. They may grow in size, especially during pregnancy. Fibroadenomas often get smaller after menopause (if a woman is not taking hormone replacement therapy).

Exams and Tests

After a physical examination, one or both of the following tests are usually done:

• Breast ultrasound
• Mammogram

A core needle biopsy may be done to get a definite diagnosis. Women in their teens or early 20s may not need a biopsy if the lump goes away on its own or if the lump does not change over a long period of time.

For more information on the different types of breast biopsies, see:

• Breast biopsy - open
• Breast biopsy - stereotaxic
• Breast biopsy - ultrasound (core needle)

Treatment

If a biopsy shows that the lump is a fibroadenoma, the lump may be left in place or removed.

The decision to remove the lump is made by the patient and the surgeon. Reasons to have it removed include:

• Abnormal biopsy results
• Pain or other symptoms occur
• Worry or concern about cancer

If the lump is not removed, your health care provider will watch to see if it changes or grows. This may be done using

• Mammogram
• Physical examination
• Ultrasound

Sometimes, the lump may be destroyed without removing it, using freezing. This is called cryoablation.

Outlook (Prognosis)

Women with fibroadenoma have a slightly higher risk of breast cancer later in life. Lumps that are not removed should be checked regularly by physical exams and imaging tests, following the doctor's recommendations.

Possible Complications

If the lump is left in place and carefully watched, it may need to be removed at a later time if it changes or grows.

In very rare cases, the lump may be cancer. You may need further treatment.

When to Contact a Medical Professional

Call your health care provider if you have a lump that is thought to be a fibroadenoma and it grows or changes in any way.

References

Iglehart JK, Smith BL. Diseases of the breast. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 34.

Valea FA, Katz VL. Breast diseases: diagnosis and treatment of benign and malignant disease. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2007:chap 15.

Miltenburg DM, Speights VO Jr. Benign breast disease. Obstet Gynecol Clin North Am. 2008;35:285-300.

Updated: 4/16/2012

Reviewed by: David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., Debra G. Wechter, MD, FACS, General Surgery practice specializing in breast cancer, Virginia Mason Medical Center, Seattle, Washington.