Definition of Fibroadenoma - breast:

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

Causes, incidence, and risk factors:

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).

Signs and tests:

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

• Breast ultrasound
• Mammogram

A core needle biopsy must be performed 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 - sterotaxic
• 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
• Shape of the breast has changed
• Worry or concern about cancer

If the lump is left in place, it may be watched over time with:

• Mammogram
• Physical examination
• Ultrasound

Alternative treatments include removing the lump with a needle and destroying the lump without removing it (such as by freezing, in a process called cryoablation).

Expectations (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.

Complications:

If the lump is left in place and carefully watched, it may need to be removed at a later time if it changes, grows, or doesn't go away.

In very rare cases, the lump may be cancerous and you may need further treatment.

Calling your health care provider:

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.