What Is Fibroadenoma?
A fibroadenoma is a common benign (non-cancerous) solid breast lump. It is made of both glandular and fibrous tissue and often feels smooth, rubbery and easily movable under the skin.
How Common Is It?
Fibroadenomas are among the most frequent breast lumps in young women, especially between the ages of 15 and 35. They can also occur in older women, particularly those using hormone therapy.
Some women have more than one fibroadenoma in one or both breasts.
Causes & Risk Factors
The exact cause is not fully understood, but fibroadenomas appear to be hormone-sensitive. They may grow during times of higher estrogen, such as pregnancy, and shrink after menopause.
Risk factors can include:
- Young age with active menstrual cycles.
- Use of hormone therapy.
- Family tendency to develop benign breast lumps.
Symptoms
Many fibroadenomas are found incidentally and cause no pain. When symptoms occur, they may include:
- A distinct, round or oval lump that moves easily when you press it ("breast mouse").
- Usually painless, but may feel tender, especially before menstruation.
- Most often located in the upper outer part of the breast, but can appear anywhere.
When Should You See a Doctor?
Any new breast lump should be evaluated by a clinician, even if it feels like a typical fibroadenoma.
You should see a doctor if:
- You feel a new lump or an existing lump changes in size, shape or firmness.
- The lump becomes painful or the overlying skin changes.
- You have a strong family history of breast cancer or carry a known genetic mutation.
How Is It Diagnosed?
Diagnosis begins with a clinical breast exam.
Imaging tests may include:
- Breast ultrasound – very helpful in younger women; fibroadenomas typically appear as well-defined, solid lesions.
- Mammography – more commonly used in women over 40 or when indicated by risk.
In many cases, a core needle biopsy is recommended to confirm that the lump is a fibroadenoma and not another type of lesion.
Treatment Options
Management depends on the size of the fibroadenoma, your age, symptoms and personal preferences.
Conservative (non-surgical) management:
- If the lump is small, has typical benign features on imaging and biopsy, and is not growing, your doctor may recommend regular follow-up with ultrasound.
- Surgical or minimally invasive options:
- Surgical excision (lumpectomy) – removal of the fibroadenoma through a small incision, often as a day-case procedure.
- Vacuum-assisted excision or other minimally invasive techniques may be available in some centers.
Removal is usually considered if the fibroadenoma is large, growing, causing discomfort, cosmetically disturbing, or if there is any doubt about the diagnosis.
Is It Cancerous?
Typical fibroadenomas are benign and do not turn into cancer.
In rare cases, complex fibroadenomas or those with atypical cells may carry a slightly increased risk of developing breast cancer in the future. Your doctor will advise you if closer follow-up is needed.
Can It Affect Fertility or Pregnancy?
Fibroadenomas do not affect fertility or the ability to have a normal pregnancy.
They may enlarge during pregnancy due to hormonal changes, and sometimes shrink afterward.
Key Takeaways for Patients
- Fibroadenomas are common, benign breast lumps, especially in younger women.
- Any new lump still needs proper imaging and often biopsy to confirm the diagnosis.
- Many fibroadenomas can be safely monitored; others may be removed if large, growing or bothersome.
- Having a fibroadenoma does not mean you have breast cancer.