Fibroadenoma on Ultrasound: What Does It Mean and What Happens Next?

A fibroadenoma on ultrasound means the scan shows a solid, usually smooth, well-defined lump that looks like this common benign growth. Fibroadenomas are made of glandular and fibrous breast tissue and are not cancer. A biopsy is often used to confirm the finding.

MedlinePlus describes fibroadenoma as the most common breast tumour in women under 30. Cleveland Clinic says they occur most often between ages 15 and 35 and become uncommon after menopause. They usually feel firm or rubbery, smooth and easy to move, and are often painless.

Some people have more than one fibroadenoma, in one or both breasts. They can grow during pregnancy and often shrink after menopause. Men can rarely develop one. A fibroadenoma is different from a breast cyst: a cyst is a fluid-filled sac, while a fibroadenoma is solid tissue, and ultrasound is the test that usually tells the two apart.

This guide explains general report wording and common next steps. It cannot interpret your own images.

Breast Cancer Now advises going back to your GP or breast clinic if a fibroadenoma gets bigger or if you notice any other breast change, however long ago it was diagnosed. MedlinePlus lists these changes to report:

• A new breast lump, or a known lump that grows or changes.
• Redness of the breast skin, or skin that looks like orange peel.
• Dimpling or puckering of the skin, or a nipple that has newly turned inward.
• Clear or bloody nipple discharge, or unexplained bruising of the breast.

Usually a GP refers a person with a breast lump to a breast clinic. Tests may include a breast examination, ultrasound, mammogram and biopsy. Breast Cancer Now notes that women under 40 are more likely to have an ultrasound than a mammogram, because denser breast tissue in younger women can make mammograms less clear.

Ultrasound shows whether a lump is solid or filled with fluid, and its shape and edges. Fibroadenomas are usually round or oval with clear, smooth borders. Imaging alone cannot always tell one solid lump from another, which is why a biopsy is often advised.

A core needle biopsy, usually guided by ultrasound, takes small tissue samples for the laboratory. According to MedlinePlus and Breast Cancer Now, teenagers and women in their early 20s, or under 25, may not need a biopsy, for example if the lump disappears or stays the same over time. Your breast team decides this based on your age, examination and scan.

Pathology or imaging reports sometimes add a type. These terms describe how the tissue looks or how large the lump is:

• Simple fibroadenoma: the most common type. Breast Cancer Now says most are about 1 to 3 cm and do not raise future breast cancer risk.
• Complex fibroadenoma: some cells look different under the microscope, and there may be features such as small cysts or calcifications. This very slightly increases future breast cancer risk and is more common in older women.
• Giant fibroadenoma: larger than 5 cm. These most often develop during pregnancy or breastfeeding.
• Juvenile fibroadenoma: found in teenage girls. Breast Cancer Now notes that growth is more likely in this age group.

Often not. Breast Cancer Now says most fibroadenomas need no treatment or follow-up. Most stay the same size, some shrink or disappear, and a few grow, especially in teenage girls. They may grow during pregnancy, breastfeeding or HRT and then usually shrink again.

When a lump is left in place, some teams arrange monitoring with examination, ultrasound or mammogram. Cleveland Clinic describes follow-up every three to six months in some cases, but practice varies, and many people are simply asked to come back if the lump changes.

Removal may be considered when the biopsy result is unclear, the lump grows, causes pain or is very large, or it is a giant, complex or juvenile type. You can also ask about removal if the lump bothers you, though Breast Cancer Now notes this may not relieve every symptom.

The main options described by Breast Cancer Now, MedlinePlus and Cleveland Clinic are:

• Surgical excision: the lump is cut out, usually under general anaesthetic.
• Vacuum-assisted excision: for smaller fibroadenomas, a probe guided by ultrasound removes the lump through a small cut under local anaesthetic. It can cause bruising and may leave a slight dent.
• Ablation: some centres destroy the lump without removing it, by freezing (cryoablation) or heating with radiofrequency energy, guided by ultrasound.

For most people, a fibroadenoma does not increase breast cancer risk. Cleveland Clinic says it rarely turns into cancer, and in very rare cases cancer is found within one. A complex fibroadenoma slightly raises future risk.

This is why a confirmed diagnosis and a plan for changes matter. Keep up with routine screening as advised for your age, and report new breast changes rather than assuming they are the same lump.

If you are worried about your overall breast cancer risk, for example because of family history, Breast Cancer Now suggests talking to your GP or breast team. They can explain whether a finding such as a complex fibroadenoma changes anything in your case.

These questions can help you understand the result and the plan:

• Has the fibroadenoma been confirmed by biopsy, or is it based on the scan alone?
• Is it described as simple, complex, giant or juvenile, and what BI-RADS category was given?
• Do I need follow-up scans, and if so, when and with whom?
• What size or change would lead you to suggest removal?
• If I want it removed, which method would suit its size and position, and what are the downsides?
• Does this finding change my routine screening?

On SameCase, patients and verified doctors share de-identified cases. Seeing how other people with a fibroadenoma weighed monitoring against removal can help you list questions before your appointment.

We do not diagnose, and someone else's experience cannot predict yours. Take your questions to the breast team that has your scan and biopsy results.