Fibroadenomas are common benign (non-cancerous) breast tumors made up of both glandular tissue and stromal (connective) tissue. Fibroadenomas are most common in women in their 20s and 30s, but they can be found in women of any age. They tend to shrink after a woman goes through menopause
A fibroadenoma is usually felt as a lump in the breast which is smooth to the touch and moves easily under the skin.
Fibroadenomas are usually painless, but sometimes they may feel tender or even painful, particularly just before a period.
Most Fibroadenomas are about 1–3cm in size and are called simple Fibroadenomas. When looked at under a microscope, simple Fibroadenomas will look the same all over.
Simple Fibroadenomas do not increase the risk of developing breast cancer in the future.
Some Fibroadenomas are called complex fibroadenoma. When these are looked at under a microscope, some of the cells have different features.
Having a complex fibroadenoma can vary slightly increase the risk of developing breast cancer in the future.
Occasionally, a fibroadenoma can grow to more than 5cm and may be called a giant fibroadenoma. Those found in teenage girls may be called juvenile Fibroadenomas.
It’s not known what causes a fibroadenoma. It’s thought that it probably occurs because of increased sensitivity to the hormone estrogen. Or if the man hold and play with the breast very hard for long time and can injure the fiber tissue.
Breasts are made up of lobules (milk-producing glands) and ducts (tubes that carry milk to the nipple). These are surrounded by glandular, fibrous and fatty tissue. This tissue gives breasts their size and shape.
Fibroadenomas develop from a lobule. The glandular tissue and ducts grow over the lobule and form a solid lump.
Fibroadenomas are often easier to identify in younger women. If you’re in your early 20s or younger, your fibroadenoma may be diagnosed with a breast examination and ultrasound only. However, if there’s any uncertainty about the diagnosis, a core biopsy or FNA will be done.
If you’re under 40, you’re more likely to have an ultrasound than a mammogram. Younger women’s breast tissue can be dense which can make the x-ray image less clear so normal changes or benign breast conditions can be harder to identify. However, for some women under 40, mammograms may still be needed to complete the assessment.
In most cases you’ll not need any treatment or follow-up if you have a fibroadenoma. Usually you’ll only be asked to go back to your GP or the breast clinic if it gets bigger or you notice a change.
Most Fibroadenomas stay the same size. Some get smaller and some eventually disappear over time. A small number of Fibroadenomas get bigger, particularly those in teenage girls. Fibroadenomas can also get bigger during pregnancy and breastfeeding or while taking hormone replacement therapy (HRT), but usually reduce in size again afterwards.
Sometimes an operation, called an excision biopsy, is needed to remove a fibroadenoma if it’s a large, complex or juvenile fibroadenoma. You can also ask to have a fibroadenoma removed. This is usually performed under general anesthetic.
Your surgeon may use dissolvable stitches placed under the skin which will not need to be removed. However, if a non-dissolvable stitch is used, they’ll need to be taken out about a week after surgery. You’ll be given information about looking after the wound before you leave hospital.
You may be offered a vacuum assisted excision biopsy to remove the fibroadenoma. This is a way of removing small Fibroadenomas under local anesthetic, without having an operation under general anesthetic.
After an injection of local anesthetic, a small cut is made in the skin. A hollow probe connected to a vacuum device is placed through this. Using an ultrasound as a guide, the fibroadenoma is sucked through the probe by the vacuum into a collecting chamber. The biopsy device is used in this way until all of the fibroadenoma has been removed. This may mean that surgery can be avoided.
The removed tissue is sent to a laboratory and examined under a microscope.
Steve Ramsey, PhD. MSc medical ultrasound