Fibroadenomas (fy-broe-ad-uh-NO-muhz) are solid, noncancerous breast tumors that most often occur in adolescent girls and women under the age of 30.
A fibroadenoma is a firm, smooth, rubbery or hard lump with a well-defined shape. It moves easily under your skin when touched and is usually painless. Typically about the size of a marble, fibroadenomas can enlarge during pregnancy and breast-feeding.
Fibroadenomas are one of the most common breast lumps in young women. Treatment may include careful monitoring to detect changes in the size or feel of the fibroadenoma, or surgery to remove it.
Fibroadenomas are solid breast lumps or masses that usually are:
A fibroadenoma may feel like a marble within your breast when you press on it. You can have one or many fibroadenomas. The average fibroadenoma is about an inch (2.5 centimeters) in diameter. Those larger than 2 inches (5 centimeters) are called giant fibroadenomas.
Fibroadenomas first occurring during adolescence are called juvenile fibroadenomas. They can grow rapidly and become as large as 4 inches (10 centimeters) in diameter.
When to see a doctor
The cause of fibroadenomas is unknown. However, fibroadenoma development is probably related to reproductive hormones. Fibroadenomas occur in greater frequency during your reproductive years, can increase in size during pregnancy or estrogen therapy, and tend to shrink after menopause, when estrogen stimulation decreases.
Most fibroadenomas don't affect your risk of breast cancer. However, your breast cancer risk might increase slightly if you have a complex fibroadenoma — which may contain cysts or bits of dense, opaque tissue called calcifications.
Preparing for your appointment
You probably will discuss your breast lump with your family doctor or your gynecologist.
What you can do
Questions to ask your doctor:
What to expect from your doctor
Tests and diagnosis
During the physical exam, your doctor will check both breasts for lumps and other problems. Depending on your age and the characteristics of the lump, your doctor may recommend one or more of the following tests:
In fine-needle aspiration, your doctor inserts a thin, hollow needle into your breast and draws fluid out of the lump with a syringe. ...
Treatments and drugs
In many cases, no treatment is necessary. However, most women choose to have their fibroadenomas surgically removed just for their peace of mind.
You might decide to avoid surgery because:
If you choose not to have a fibroadenoma removed, continued monitoring is important to make sure it doesn't grow larger. At any time that you become overly anxious about the fibroadenoma, you can reconsider surgery.
The procedure to remove a fibroadenoma is called a lumpectomy or excisional biopsy. The tissue will be examined in a lab to check for cancer. After a fibroadenoma is removed, it's possible that one or more new fibroadenomas may develop.
New lumps need to be assessed with mammograms, ultrasound and possibly biopsy — to determine if the lump is a fibroadenoma or cancer. You may need another surgery to remove the fibroadenoma if leaving it in place makes you anxious.
Last Updated: 2011-05-27
© 1998-2014 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use