Fat necrosis

1. Fat necrosis is a benign (not cancer) breast condition
2. It usually feels like a firm, round lump in the breast
3. Fat necrosis can form if an area of fatty breast tissue becomes damaged
4. It most commonly happens after an injury or trauma to the breast tissue, such as breast surgery
5. Having fat necrosis does not increase your risk of developing breast cancer

Common symptoms of fat necrosis can include:

• A firm, round lump or lumps in the breast, which are usually painless
• Thickened, red or bruised skin around the lump

Less common symptoms include:

• Tenderness or pain
• Dimpled skin or indentation around the lump
• The nipple being pulled in (inverted)

Fat necrosis can affect women of any age, but it’s more common in women around the age of 50.

Men can also get fat necrosis, but this is rare.

Fat necrosis can form if an area of fatty breast tissue becomes damaged. Necrosis is a medical term for damaged or dead tissue.

It can be caused by any type of trauma or injury to the breast. This can include:

• Damage or injury caused by an accident such as a seatbelt injury or fall
• Breast surgery including lumpectomy, breast reduction, breast reconstruction or enlargement
• Breast biopsy
• Radiotherapy to the breast
• Fat transfer (lipomodelling) – when fat taken from one part of the body is injected into the breast

Fat necrosis can be found at any time after breast surgery or an injury.

Sometimes it develops without any trauma and many people with fat necrosis don’t remember a specific injury.

After you have a breast examination, your GP is likely to refer you to a breast clinic where you’ll be seen by specialist doctors or nurses.

At the breast clinic, you may have:

• A breast examination
• Mammogram
• Ultrasound scan
• Core biopsy
• Fine needle aspiration (FNA)

Fat necrosis can sometimes look like breast cancer on mammograms and scans.

If the mammogram or ultrasound scan clearly shows that the lump is fat necrosis, you may not need more tests. If there’s any doubt about what the mammogram or ultrasound scan shows, you’ll have a biopsy.

If you’re under 40, you’re more likely to have an ultrasound than a mammogram. Younger women’s breast tissue can be denser which can make the x-ray image less clear. However, you may still need a mammogram to complete your assessment.

Fat necrosis does not usually need treatment

Fat necrosis is harmless so you will not usually need any treatment or follow-up.

In most cases the body will break down the fat necrosis naturally over time. Depending on the size of the lump, this can take several months and sometimes years.

It’s important to go back to your GP if you notice any changes to the area of fat necrosis or anywhere else in your breasts.

Surgery 

Surgery is usually avoided if possible because it can sometimes cause further fat necrosis.

However, an operation to remove your fat necrosis may be recommended if:

• The biopsy has not given enough information to confirm a diagnosis of fat necrosis
• The area of fat necrosis is uncomfortable or tender
• The lump or lumpy area does not go away by itself or gets bigger

Excision biopsy 

If you need surgery, you’ll usually have an excision biopsy.

This is an operation to remove the dead or damaged tissue. This can be done using either a local anaesthetic (where the area is numbed) or general anaesthetic (medication to make you sleep).

The operation will leave a scar.

Vacuum assisted excision biopsy

You may be offered a vacuum assisted excision biopsy to remove your fat necrosis.

This involves making a small cut in the skin under local anaesthetic. Breast tissue is then sucked out using a special device until the fat necrosis is removed.

Any tissue removed is sent to the laboratory and examined under a microscope.

Pain relief 

If your fat necrosis causes discomfort but you’re not having an operation to remove it, your doctor may suggest treating it with pain relief such as paracetamol or an anti-inflammatory drug like ibuprofen.

Breast cysts

Sometimes, within an area of fat necrosis the damaged tissue breaks down to an oily fluid that can form as a cyst (oil cyst).

Breast cysts do not usually need any treatment or follow-up. Most cysts go away by themselves and are nothing to worry about.

If the cyst is large or causing discomfort, your specialist may draw off the fluid using a fine needle and syringe.

Learn more about breast cysts.

Having fat necrosis does not increase your risk of developing breast cancer in the future.

But it’s important to go back to your GP if you notice any changes in your breasts, no matter how soon after your diagnosis of fat necrosis.