Breast Fat Necrosis: Causes, Signs and Treatment

While finding any lump in the breast is frightening, breast fat necrosis is not breast cancer. It can, however, take time and patience to determine if that lump is a sign of breast fat necrosis or something more serious.

The condition can mimic breast cancer on a physical exam, mammogram, or other imaging tests. This makes it difficult to differentiate from breast cancer without having multiple diagnostic tests to confirm the diagnosis.

We spoke with breast experts to understand what exactly breast fat necrosis is, what causes it, and when doctors recommend surgery to remove it.

Breast fat necrosis is a lump caused by damaged, inflamed, or dead fatty tissues and cells in the breast that result in scar tissue formation. While the lump varies in size and appearance, it may feel like a mass or an area of thickening.

"Fat necrosis of the breast is a benign condition that commonly occurs as the result of breast trauma (22-70%) or surgical intervention, said Amy Bremner, MD, a breast surgical oncologist and medical director of breast surgical oncology at MemorialCare Saddleback Medical Center in Laguna Hills, California.

When a breast injury occurs, healthy tissues and cells become damaged and, in turn, begin to die. The body responds by creating scar tissue that accumulates to form a lump. This type of lump usually feels firm and may or may not be tender or painful to the touch. Your nipple may also become retracted or inverted due to the scar tissue pulling on it.

“Any procedure that disrupts the breast’s fatty tissue can lead to breast fat necrosis,” according to Michele B. Drotman, MD, FACR, division chief of women’s imaging and an attending physician at New York Presbyterian Hospital. The result, she said, may be a palpable lump.

Some of the most common causes include:

• History of a surgical procedure, such as a breast biopsy or lumpectomy

• Mastectomy

• Breast reconstructive surgery

• Breast implant placement or removal

• Radiation therapy for breast cancer treatment

• Breast reduction surgery

• Breast trauma, such as a car accident or sports injury

These procedures can cause damage to the fatty tissue and blood vessels of the breast. “Damaged breast tissue is replaced with scar tissue. When fat cells die, a greasy fluid is released and collects into an oil cyst,” Dr. Drotman explained. “It can develop up to 10 years after having a procedure,” but it forms in only “a small number of cases.”

Smoking, obesity, and older age may increase your risk of developing breast fat necrosis, according to Dr. Bremner.

"The most common presenting symptom is an irregular breast mass," said Dr. Bremner. Depending on the severity of the damage to the breast tissue, people with breast fat necrosis may also experience one or more of the following:

• Changes in the shape or appearance of the breast

• Breast dimpling or puckering

• Skin irritation or redness on the breast surface

• Nipple inversion, where the nipple is pulled inward

• Discharge from the nipple

• Breast pain or discomfort, especially when touched

• Swollen axillary lymph nodes (located under the arm)

If your doctor suspects fat necrosis, they may recommend imaging to confirm this.

Mammography is the most helpful imaging tool for diagnosis, particularly in its early stages. Your doctor may recommend an ultrasound or breast MRI to rule out other conditions. A biopsy may be necessary, especially if the lump appears suspicious for cancer.

"Fat necrosis can be confused with cancer on physical examination and may mimic cancer on imaging studies," said Dr. Bremner. "It is sometimes necessary to biopsy these lesions to confirm the diagnosis, although experienced radiologists can usually determine that a lesion represents fat necrosis based on mammographic and ultrasound findings."

The condition can look like a simple or complex cyst on an ultrasound, Dr. Drotman added. A cyst is a fluid-filled sac that can form on or in the breast. They are not typically cancerous.

In most cases, breast fat necrosis does not require treatment and resolves on its own over time. However, treatment may be necessary if the condition is causing pain or discomfort.

“It can take several months for the breast fat necrosis to break down,” said Dr. Drotman. Surgery to remove the area might be considered if:

• The diagnosis cannot be confirmed through biopsy

• The lump continues to get larger rather than smaller over time

• You experience significant pain or discomfort that affects daily activities

• There is uncertainty regarding whether the lump is cancerous and requires removal for a definitive diagnosis

• The cosmetic appearance of the breast is severely affected

If your doctor does not recommend surgery, they may suggest a follow-up mammogram or ultrasound to monitor for changes. However, Dr. Bremner notes that having the condition does not increase your risk of subsequent breast cancer.

Breast fat necrosis isn't cancer, nor does it raise your risk of getting cancer in the future. It's a benign condition that can mimic the appearance and symptoms of cancer.

Any kind of damage to the breast tissue can lead to fat necrosis, and it's not always preventable. If you notice any changes in your breast, such as a new lump or skin irritation, it's important to see your doctor for an evaluation. While many cases of breast fat necrosis resolve on their own, it's always best to get a proper diagnosis and follow-up care.

It usually takes more than one diagnostic test to confirm, which may include a mammogram, ultrasound, and biopsy. However, once diagnosed, most people do not require treatment and can continue to monitor the condition with regular check-ups.

Talk to your doctor if you have any concerns about breast fat necrosis or if you notice changes in your breast tissue.