Breast Fat Necrosis—Symptoms, Causes and Treatments

Distinguishing Fat Necrosis vs Breast Cancer

What exactly is fat necrosis of the breast? If your doctor has diagnosed you with this problem you're likely confused and worried, especially since it can look so much like a breast cancer on imaging tests such as a mammogram. How does fat necrosis happen? Could it lead to breast cancer? Will it go away on its own or does it need to be treated?

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

Unfortunately, breast fat necrosis is a common problem and poses a challenge to physicians and women alike. The problem with fat necrosis in the breast is that it often looks and feels like breast cancer, and can look like breast cancer on a mammogram even though it is benign. In fact, the symptoms can be terrifying if you are familiar with the symptoms of breast cancer. Some people are frightened, wondering how their doctors can be sure they "only" have breast fat necrosis.

Fat necrosis may take many forms and can be hard to diagnose. Let's take a look at the symptoms, causes, and treatments for breast fat necrosis, and how you and your doctor can determine that this is what's causing your lump.

What is Fat Necrosis of the Breast?

woman holding her hand above her breast palpating
What is fat necrosis of the breast and what are the causes?. Rob Gage/Getty Images

Fat necrosis is a benign breast 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, or any type of breast injury.

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 fat necrosis - Adding to the anxiety created by a diagnosis of fat necrosis are the number of terms which are used to describe it that mean the same thing. Fat necrosis may also be called:

  • Membranous fat necrosis
  • Liponecrosis microcystica calcificata
  • Post-traumatic 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—in essence, the same kind of symptoms which are common with breast cancer.

Your breast may feel tender or painful surrounding the area of fat necrosis, but this is not always the case, and often the area of necrosis is painless (again mimicking breast cancer.)

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. Once again, these are symptoms we are all told to watch for as possible symptoms of breast cancer. 

If you have an oil cyst, it may feel like a smooth and squishy lump, similar to the feeling of a small grape under your skin.

In one study on breast fat necrosis it was found that 97 percent could be felt (were palpable) and two-thirds were painless.

Characteristics of fat necrosis in one study found that:

  • The lumps are often periareolar (around the nipple) and superficial (are felt just under the skin)
  • Bruising or tenderness was noted 24 percent of the tie.
  • Skin tethering or dimpling was noted in 14 percent.
  • Nipple retraction was present in 9 percent.

After the area of breast fat necrosis appears it may increase in size, decrease in size, or stay the same. It may persist for years or may resolve leaving behind fibrosis and calcifications (which may be seen on a mammogram.)

Causes of Breast Fat Necrosis

There are a wide variety of causes for fat necrosis in the breast.

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 and can be mistaken for a breast cancer recurrence. It appears to be more common in women who have accelerated partial radiation and radiologists are looking for better ways to evaluate this, including the use of a grading system.

For those who have surgery for breast cancer, it is more common among those who receive adjuvant chemotherapy. Fat necrosis is becoming more of a concern with fat grafting during reconstruction and differentiating fat necrosis from a recurrence of breast cancer.

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.

Breast fat necrosis can also cause false positive findings on a PET scan.

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 Advil (ibuprofen) and aspirin. If your pain is severe, you may need to ask your doctor for a prescription pain medicine.

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, but make sure to talk to your doctor even if your symptoms are gone.

Bottom Line on Fat Necrosis of the Breast

Breast cancer necrosis can be frightening for women and a challenge for physicians. That said, through a combination of imaging studies, and a biopsy if needed, you and your doctor can make sure that you are coping with fat necrosis alone and nothing worse. 

Sources:

Adejolu, M., Huo, L., Rohren, E., Santiago, L., and W. Lang. False-Positive Lesions Mimicking Breast Cancer on FDG PET and PET/CT. AJR American Journal of Roentgenology. 2012. 198(3):W304-14.

Ayyappan, A., Crystal, P., Torabi, A., Foley, B., and B. Fornage. Imaging of Fat-Containing Lesions of the Breast: A Pictorial Essay. Journal of Clinical Ultrasound. 2013. 41(7):424-33.

Hickey, B., Lehman, M., Francis, D., and A. See. Partial Breast Irradiation for Early Breast Cancer. Cochrane Database of Systematic Reviews. 2016. 7:CD007077.

Kerridge, W., Kryvenko, O., Thompson, A., and B. Shah. Fat Necrosis of the Breast: A Pictorial Review of the Mammographic, Ultrasound, CT, and MRI Findings with Histopathologic Correlation. Radiology Research and Practice. 2015. 2015:613139.

Taboada, J., Stephens, T., Krishnamurthy, S. et al. The Many Faces of Fat Necrosis in the Breast. American Journal of Roentgenology. 2009. 192(3):815-825.

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