Lipomas are the most common fatty tumors of the breast. But unlike many other types of tumor, lipomas have few if any symptoms.
Read on to find out what breast lipomas are, what symptoms they can cause, and whether they can be successfully treated.
Breast lipomas are benign (noncancerous) tumors that develop from soft tissue cells known as mesenchymal cells. These cells help form and support vital tissues such as your:
- adipose (fatty) tissue
Lipomas in the breast tend to be slow-growing tumors that sit just underneath the skin. They are not made of breast tissue but of mature fat cells encased within thin, fibrous capsules.
These fatty masses often weigh only a few grams (g) and measure less than a centimeter (cm), although some can grow larger.
Giant breast lipomas are those that weigh more than 500 g and measure more than 10 cm. They form a bulge that can be seen on the surface of the breast.
Breast lipomas that are large enough to be felt under the skin tend to be soft and doughy to the touch and move around freely. They do not bind or pull in the skin over it. Instead, the mass slips out from under your fingers if you gently push it.
These benign tumors do not usually cause breast symptoms but may be painful if a lipoma affects nearby nerves, blood vessels, or joints.
Breast lipomas may form one at a time or in clusters.
There are several ways a lipoma in the breast may be discovered and diagnosed. These include:
- Physical exam. A doctor or healthcare professional will start with a physical exam, and this may be enough to diagnose a lipoma.
- Imaging studies. Although imaging studies may not be needed to diagnose a lipoma, your healthcare professional will likely suggest one or more of these tests if the mass in your breast is new.
- Mammogram. A breast lipoma that you cannot feel may be found incidentally during a routine mammogram. The mass may be clearly seen on a mammogram of your breasts, and its classic appearance may be enough to confirm the diagnosis.
- Ultrasound of the breast. In some cases, your doctor may also order other imaging tests such as a breast ultrasound to distinguish between a benign (noncancerous) breast lipoma and malignant (cancerous) liposarcoma. However, a breast biopsy may be needed for an accurate diagnosis.
- Breast biopsy. A mammogram or breast ultrasound may not clearly show a breast lipoma. The fatty tissues of the breast may blend with those of the tumor, or it may be covered by glandular tissues that form the glands and ducts within the breast. A surgeon may perform a breast biopsy, which involves removing the mass and sending the tissue to a lab for examination by a pathologist to look for evidence of cancer.
It is unclear what exactly causes lipomas in the breast. Some
Lipomas of the breast may also run in families. They have been linked to gene and chromosome deletions, mutations, and rearrangements.
They may also occur more often in people with certain syndromes, such as:
You may not need treatment for breast lipomas, since most are harmless and do not cause pain or other symptoms. Your doctor may choose to observe lipomas in the breast to be sure they do not grow too large or fast or cause symptoms or other issues.
If you do not like the look of lipomas in the breast, you may consider having the lipoma surgically removed.
Your doctor may suggest treatment if lipomas in your breast are:
- large (e.g., larger than 10 cm)
- growing rapidly
- seated in precarious sites such as deep tissue or close to nerves or joints
- connected to underlying tissues
Options for breast lipoma removal involve:
- Surgical excision. This involves removing the entire mass along with its fibrous capsule to lessen the risk of the lipoma returning.
- Liposuction. This can be used to break down and suction out breast lipoma clusters or single tumors that are medium-sized (4 to 10 cm) and larger. A
2017 studycited numerous advantages to this approach, such as:
- smaller and fewer scars
- less pain
- lower complication rates
- ability to remove lipomas from distant sites
Another treatment approach involves shrinking these tumors by injecting them with medications such as steroids before surgery. Even without surgery, these injections may break down the tumor enough for the body to get rid of it. At times, the breast lipoma may not be fully eliminated and may be more likely to recur.
Breast lipomas have an excellent outlook.
They rarely recur at the same site on your breast once the tumor and its fibrous capsule have been fully removed, although a new lipoma may form in other parts of your breast or body.
If left untreated, they tend to grow slowly and remain benign. But if they grow at a fast rate, cause pain or other troublesome symptoms, or change in unusual ways, it is vital to promptly meet with a healthcare professional.