Fat necrosis refers to dead or damaged breast tissue that often manifests as a noncancerous lump under the skin. In most cases, these lumps go away on their own and don’t return.
Fat necrosis of the breast occurs when fat and oil collect into a lump that you can feel in your breast tissue. This type of lump isn’t cancerous, and it may be sore or painful for some people.
When fatty breast tissue gets damaged, a lump of dead or damaged tissue can form. Fatty breast tissue is the outer layer of the breast beneath the skin.
It can be difficult to tell the difference between lumps caused by fat necrosis and those resulting from breast cancer on a mammogram. In order to make an accurate diagnosis, a doctor may need to take a sample of the tissue (breast biopsy).
Fat necrosis is a noncancerous lump in the breast that develops from dead breast tissue. Necrosis means cell death, which happens when cells do not get enough oxygen.
When breast tissue is damaged, fat cells die and release oils that form small sacs called cysts. Over time, these cysts can harden and lead to the formation of scar tissue.
Fat necrosis commonly develops after breast surgery, radiation, or other traumatic injuries to the breast. While the lumps can cause some worry initially, they are harmless in terms of your overall health and don’t increase your risk of developing breast cancer.
What to do about a breast lump
Talk with a doctor as soon as you can about any lumps you feel in your breast. They can do an exam and run any necessary tests to confirm the cause of the lump.
Most of the time, fat necrosis goes away on its own, and any pain or tenderness from the necrosis can be treated.
Fat necrosis causes a firm lump or mass to form in your breast. It’s usually painless, but it can feel tender to some people.
You might also notice some skin discoloration or bruising around the lump, but there are rarely any other symptoms.
It can be nearly impossible to tell the difference between a fat necrosis lump and a breast cancer lump by a physical exam or even with a mammogram. If you find a lump in your breast, it’s important you see a doctor.
Breast fat necrosis vs. breast cancer symptoms
While it’s difficult to tell the difference between fat necrosis and breast cancer without a biopsy, there are some symptoms that may appear with breast cancer that you would not have with a lump caused by fat necrosis. Signs of breast cancer may also vary depending on how advanced the condition is.
Possible signs of breast cancer may include:
- nipple discharge
- changes to your nipple, such as turning inward
- scaling or thickening of the skin around your breast, which is also known as peau d’orange
- swollen lymph nodes under your arm or collarbone
- a lump that grows or changes in shape
It’s not likely that you would experience any of these symptoms with a lump caused by fat necrosis, so it’s best to see a doctor if you notice any of these signs.
Learn about the early signs of breast cancer.
Breast fat necrosis vs. oil cyst symptoms
Oil cysts can also cause a lump in your breast and sometimes form along with fat necrosis.
Oil cysts are noncancerous, fluid-filled sacs that form when the oils from decomposing fat cells collect in one place instead of hardening into scar tissue. Your body coats the oil sac with a layer of calcium (calcification), and the sac may feel:
- smooth
- squishy
- flexible
Similar to a lump caused by fat necrosis, a lump is probably the only symptom you’ll notice with an oil cyst. These cysts might show up on mammograms, but they’re usually diagnosed with a breast ultrasound.
Oil cysts usually go away on their own, but a doctor can drain the fluid inside the cyst with a
Fat necrosis may often result from breast surgery, radiation, or other trauma, such as an injury to the breast.
The most common cause is surgery, including:
Typically,
Fat necrosis is most common after breast surgery or radiation, so having breast cancer will raise your risk of fat necrosis. Breast reconstruction after cancer surgery may also increase your risk of fat necrosis.
You may be able to feel a lump caused by fat necrosis on your own, or it may show up on a regular exam or mammogram.
If you find a lump yourself, a doctor may want to do a breast exam, and then a mammogram or ultrasound to determine the cause of the lump. They might also do a needle biopsy to test for cancer cells in the lump.
If a doctor finds a mass on a mammogram, they might follow up with an ultrasound or biopsy.
Fat necrosis usually doesn’t need treatment and will go away on its own in time. If you have pain or tenderness around the lump, over-the-counter anti-inflammatory medications like ibuprofen (Advil, Motrin) can help. You can also try massaging the area or applying a warm compress.
Larger lumps that cause more discomfort can be removed surgically, but this isn’t a common approach because surgery may cause more fat necrosis.
If fat necrosis has led to the formation of an oil cyst, a doctor may want to drain the fluid with a needle and deflate the cyst.
Fat necrosis can cause a noncancerous lump to form in your breast. These lumps may be uncomfortable or cause concern, but they rarely cause pain or require treatment.
A lump caused by fat necrosis doesn’t increase your risk of developing breast cancer or cause any other long-term problems.
A doctor may need to perform a breast biopsy to confirm fat necrosis.