Benign Breast Conditions: Fibroadenoma

June 2019
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This fact sheet describes the breast condition fibroadenoma, a benign and usually painless breast lump. If a fibroadenoma is detected during a mammogram, the woman will be recalled for assessment. For BreastScreen Aotearoa professionals to use in the programme.

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June 2019
April 2019
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The full resource:

Your mammogram (breast X-ray) from BreastScreen Aotearoa showed an area of change and you were asked to come back for assessment. The change that showed up on your mammogram was not breast cancer. It was a fibroadenoma.

What is it?

A fibroadenoma is a very common benign (non-cancerous) breast condition.

What is known about it?

  • It may be felt as a breast lump or seen on a mammogram or an ultrasound.
  • It can vary in size from a few millimetres to 5 or more centimetres in diameter.
  • If it can be felt, it usually feels like a firm, smooth, oval or round lump that can move easily within the breast.
  • It is usually painless but can be tender, especially before a period or during pregnancy.
  • Occasionally there can be multiple fibroadenomas.

What causes it?

A fibroadenoma occurs because of small hormonal changes in normal breast tissue, which cause an area to overgrow.

How common is it?

It is more common in women aged 15–40 years but can be found in women of any age.

Does it turn into breast cancer?

No. A fibroadenoma has no greater chance of developing into a breast cancer than other breast tissue. Having one or several fibroadenomas does not increase your chance of developing breast cancer.

How is it confirmed?

The diagnosis of a fibroadenoma can be confirmed by taking a sample of cells and/or tissue from the area, which is then examined under the microscope. This can be done with a needle biopsy, often guided by ultrasound.

What is done about it?

If it is proven that it is a fibroadenoma, there is usually no need to remove it.

At times, surgery is recommended to remove a fibroadenoma, for example, if it is large, growing, causing discomfort or if the diagnosis is not certain.

What happens when a fibroadenoma is not removed?

  • Most get smaller.
  • Some remain the same size.
  • A few get bigger.

What happens now?

You should continue to have mammograms at the normal two-yearly interval.

BreastScreen Aotearoa will invite you for your next mammogram when it is due.

In the meantime, if you notice a new or growing lump anywhere in either breast, see a doctor without delay.

For more information

If you have questions not answered by this sheet, ask the breastcare nurse you saw at BreastScreen Aotearoa.