Fibroadenoma of the breast is a noncancerous (benign) tumor.

Fibroadenoma is the most common benign tumor of the breast. Benign tumor means it is not caused by cancer. Fibroadenoma is 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.

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

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

Lumps may be:

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

Lumps 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 therapy).

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

• Breast ultrasound
• Mammogram

A biopsy may be done to get a definite diagnosis. Different types of biopsies include:

• Open
• Stereotatic
• Ultrasound (core needle)

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.

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

You and your surgeon can discuss whether or not to remove the lump. 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 is destroyed without removing it, using freezing. This is called cryoablation.

Women with fibroadenoma have a slightly higher risk of breast cancer later in life.

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

In very rare cases, the lump is cancer, and will need further treatment.

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

Katz VL, Dotters D. Breast diseases: diagnosis and treatment of benign and malignant disease. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 6th ed. Philadelphia, PA: Elsevier Mosby; 2012:chap 15.

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