Fibroadenoma of the breast is a benign tumor. Benign tumor means it is not a cancer.
The cause of fibroadenomas is not known. They may be related to hormones. Girls who are going through puberty and women who are pregnant are most often affected. Fibroadenomas are found much less often in older women who have gone through menopause.
Fibroadenoma is the most common benign tumor of the breast. It 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.
Fibroadenomas are usually single lumps. Some women have several lumps that may affect both breasts.
The lumps may be any of the following:
The 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:
A biopsy may be done to get a definite diagnosis. Different types of biopsies include:
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 needle biopsy shows that the lump is a fibroadenoma, the lump may be left in place or removed.
You and your health care provider can discuss whether or not to remove the lump. Reasons to have it removed include:
If the lump is not removed, your provider will watch to see if it changes or grows. This may be done using:
Sometimes, the lump is destroyed without removing it:
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 provider if you notice:
Reviewed By: Debra G. Wechter, MD, FACS, general surgery practice specializing in breast cancer, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.