Breast Fat Necrosis - Symptoms, Causes and Treatments

A Benign Breast Lump That Appears To Be Malignant

After breast surgery or after a breast injury -- from sports, accidents, or a seat belt burn -- you may develop a lump. These types of breast lumps are called breast fat necrosis because they are made of bruised, injured, or dead fatty tissue.

The problem with fat necrosis in the breast is that it often looks like breast cancer, even though it is benign. Fat necrosis may take many forms and is hard to diagnose. Take a look at the symptoms, causes, and treatments for breast fat necrosis.

What is Fat Necrosis of the Breast?

A breast exam.
A breast exam. Rob Gage/Getty Images

Fat necrosis is a benign condition that can occur in your breast. It consists of fatty tissue that has been bruised, injured, or has died. Fat necrosis can result after any type of breast surgery, from biopsy to reconstruction. Once fatty tissue has been injured or has died, it can gradually change into scar tissue or may collect as a liquid within an oil cyst. Fat necrosis does not lead to the development of breast cancer, but it may sometimes cause breast pain.

Other Terms For Breast Fat Necrosis

You may also hear this condition referred to as fat necrosis of the breast, membranous fat necrosis, liponecrosis microcystica calcificata, and/or posttraumatic pseudolipoma.

Symptoms of Breast Fat Necrosis

An area of fat necrosis in your breast may feel like a fairly hard lump, or like a section of thick skin. Your breast may feel tender or painful in the tissue near the fat necrosis. You may see some drainage from the nipple that is nearest the bruised region. Sometimes, your nipple may pull inward a little bit, or your breast skin may dimple above the lump of fat necrosis. If you have an oil cyst, it may feel like a smooth and squishy lump.

Causes of Breast Fat Necrosis

Fatty tissue in your breast may break down or die after any type of traumatic breast injury or surgery. A breast biopsy -– whether it is a needle biopsy or a surgical biopsy -– can also cause breast fat necrosis. Fat necrosis may also form around substances that have been injected into your breasts, such as silicone or paraffin. Breast radiation treatment may sometimes cause an area of fat necrosis.

Fat Necrosis Imitates Other Breast Lumps

One reason that fat necrosis can be difficult to diagnose is that it resembles several other breast lumps. Masses made of breast fat necrosis may look like malignant breast tumors on mammograms and other imaging studies. The mass may look dense, have an irregular shape, a spiky border, and a collection of microcalcifications. Fat necrosis in the breast may appear to be atypical lipoma or liposarcoma, both very rarely found in breast tissue. If the fat has turned into liquid, it can look like a cyst on an ultrasound. Breast fat necrosis can take on different appearances over time, so follow-up mammograms will show a change in the mass.

How Breast Fat Necrosis Is Diagnosed

Fat necrosis often looks and feels like many other breast lumps. If you think you have an area of fat necrosis in your breast, see your family doctor or gynecologist for a clinical breast exam. You will need to have a list of breast surgeries and recent health conditions to show your doctor. Expect to be sent for a mammogram, which may reveal a dense, malignant mass with spiculated (spiky) edges and an irregular shape. It's very likely that a breast ultrasound will come next -- as this helps find oil cysts. If neither image is conclusive, a breast MRI may be ordered. The final diagnosis may require a biopsy to confirm fat necrosis because a microscopic examination of the cells will shed the most light on your condition.

Treatment For Fat Necrosis Of The Breast

Each case of fat necrosis is unique, so treatments will vary. If your fat necrosis has occurred recently, using warm compresses may help it subside. When fat necrosis causes pain, you can use ibuprofen and aspirin, but if that doesn't help, ask your doctor if a prescription medication may be used.

In cases where a lump of fat necrosis is large and causing discomfort or distress, it may be removed with a vacuum-assisted core needle or a lumpectomy. An oil cyst can be drained with a fine needle, or it can be surgically removed.

If you have recently had a breast injury or surgery and you suspect fat necrosis, try warm compresses and gentle massage -- because with care, sometimes the tissues will heal and the necrosis will resolve on its own.


Fat necrosis of the breast. Meyer JE, Silverman P, Gandbhir L.Arch Surg. 1978 Jul;113(7):801-5.

Membranous fat necrosis of the breast: diagnosis by minimally invasive technique. Haj M, Loberant N, Salamon V, Cohen I. Breast J. 2004 Nov-Dec;10(6):504-8.

Practical MR mammography. Pp. 94 - 96. Uwe Fischer, Ulrich Brinck (M.D.) Thieme Medical Publishers, 2004.

Understanding Breast Changes, National Cancer Institute, Updated April 23, 2015.

Continue Reading