What is a lipoma?
A lipoma is a benign lump or mass that is made up of fat cells (adipocytes). Lipomas are a common, benign (noncancerous) type of slow-growing tumor and are the most common benign tumors situated under the skin. They most often develop just under the skin in the subcutaneous tissue, located beneath the skin and above the muscle. Lipomas can grow large in size, and multiple growths can develop, most commonly in the back, neck, shoulders or arms. Less commonly, lipomas can grow on almost any organ in the body.
Lipomas generally develop slowly, forming round, flattened lumps that are soft or spongy in texture and easily moved around under the skin. Lipomas can be unsightly, but they usually do not cause any pain, discomfort or tenderness.
Lipomas may begin to grow after a tissue injury or trauma, and they tend to run in families. Lipomas primarily occur in people who are middle-aged or older and are rare in children. In most cases, lipomas do not require treatment, although treatment is needed in some cases if the location or size of a lipoma causes pain, weakness, or other problems.
Seek prompt medical care if you develop a lump or swollen area. A determination of whether the lump is benign or cancerous requires a medical examination by a licensed health care provider. In rare cases, lipomas may occur in conjunction with a more serious condition, such as familial multiple lipomatosis or adiposis dolorosa.
What are the symptoms of a lipoma?
The symptoms of a lipoma typically include the formation of a lump or multiple lumps under the skin. Lipomas typically grow slowly, and you may not even notice the appearance of a lipoma for years. The most common sites for lipomas include the neck, shoulders, back, abdomen, arms or legs, but they can also grow on your internal organs.
Most often, lipomas are relatively small, about the size of a large marble. In some cases, lipomas can grow significantly larger. Lipomas develop as round, flattened lumps that feel soft and rubbery. They are not tender and are easily moved around with very little finger pressure. In most cases, a lipoma is not painful unless it is heavily squeezed or bruised. Depending on its location and size, and whether any surrounding tissues or organs are affected, a lipoma may cause pain and other problems, such as pressure on nearby nerves.
What causes a lipoma?
The reason why some people develop lipomas is not known, although family history appears to play a role. You are more likely to develop a lipoma if you have a parent or sibling with a lipoma. People who develop more than one lipoma may have an extremely rare inherited disorder called familial multiple lipomatosis.
Lipomas can also grow in subcutaneous tissue that has been injured or traumatized.
Certain factors and diseases are thought to increase your chances of developing a lipoma. However, not all people with risk factors will develop the condition. Lipomas can develop at any age, although they are rare in children and are most common in middle-aged people between ages 40 and 60.
Common risk factors for lipomas include:
- Dercum disease (also known as adiposis dolorosa, which causes multiple painful lipomas and other serious problems, such as mental health and neurological issues)
- Family history of lipomas
- Familial multiple lipomatosis (rare inherited condition involving the development of multiple benign lipomas)
- Gardner syndrome (rare inherited condition involving noncancerous or precancerous tissue masses that form in and under the skin and in different organs)
- Middle age and older
- Previous soft tissue trauma
How is a lipoma treated?
Most lipomas do not require treatment. Generally, they are only removed if they are painful or grow too quickly. You may also need to have lipomas removed if they cause serious cosmetic problems that interfere with your ability to have a normal life.
Once a lump under your skin is diagnosed as a benign (noncancerous) lipoma, your physician or health care provider will determine your best treatment option. The common treatments for benign lipomas include:
Steroid injections, which can shrink but not completely eliminate lipomas
Surgical procedures to remove lipomas (excision)
Other treatments or further diagnostic evaluations may be needed to determine the cause of the lump or to determine whether it is cancerous.
The complications of a lipoma vary depending on its location as well as whether surrounding tissues or organs are affected. Lipomas are generally not serious, but in rare cases they can press on nerves and cause pain or be associated with other serious conditions. You can treat lipomas and minimize the risk of complications by following the treatment plan you and your health care provider design specifically for you. Potential complications of lipomas include pain and possibly embarrassment from a visible deformity.