Fat Necrosis

What it is

Fat necrosis is a harmless condition where your body replaces an area of damaged fatty breast tissue with firm scar tissue. Think of it like a bruise deep inside your breast that heals into a lump. Sometimes, the damaged fat cells release their oily contents, forming a fluid filled sac called an oil cyst.

How common it is

This can happen to anyone at any age, but it is most common after breast surgery, radiation, or an injury to the breast. It can also happen on its own without a clear cause.

What you may notice

You might feel a firm, round lump that is usually painless, though it can sometimes feel tender. The skin over the area may look a little red, bruised, or even dimpled.

What can contribute

Fat necrosis is often caused by some kind of trauma to the breast. This can include an accidental bump or injury, a previous biopsy, a lumpectomy, or breast reconstruction surgery.

How it is usually checked

Your provider will likely recommend imaging, such as a mammogram or ultrasound, to get a better look. Because fat necrosis can sometimes look like other things on imaging, a biopsy is often needed to confirm that the lump is fat necrosis.

Does this change my long-term risk?

Fat necrosis is completely harmless. It does not turn into anything else and does not change your long-term breast health risk.

Comfort and everyday care

• A warm compress can help soothe any tender spots.
• Some women find that gentle massage around the area feels soothing.
• Wear a soft, supportive bra that does not dig into the tender spot.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.