What is a lipoma?
A lipoma is a knot of fatty tissue that is usually found just below the skin (subcutaneous). Lipomas can occur almost anywhere on the body, but are most commonly found on the trunk, shoulders, neck, and armpits. Lipomas can also form in muscles and internal organs.
A lipoma can be described as a rubbery bulge that feels moveable. Lipomas tend to be slow-growing, often over a period of months or years. They are usually small (usually less than two inches across). Occasionally, larger lipomas do occur, with some reaching almost eight inches across.
Lipomas are fairly common, occurring in one in every 1,000 people. People with a lipoma usually have only one, though about 20 percent of those affected can have several.
Lipomas affect all age groups and can even be present at birth; however, they usually form between the ages of 40 and 60.
Are lipomas cancerous?
A lipoma is nearly always benign, meaning it is not cancerous and will not develop into cancer. In very rare cases, a form of cancer known as liposarcoma, which occurs within fatty tissue and looks similar to a lipoma, may be present.
What causes lipomas?
The causes of a lipoma are unknown. It is possible that they are caused by a physical trauma, i.e., a blow to that part of the body. However, it is unclear whether the trauma causes a lipoma to form or if the lipoma is discovered simply as a result of medical attention to that area of the body.
In other cases, genetic conditions such as Gardner syndrome and hereditary multiple lipomatosis cause a person to have multiple lipomas. Another rare condition, Madelung’s disease, is most frequently associated with men, especially men who drink a great deal of alcohol.
What are the symptoms of lipomas?
Lipomas rarely cause pain. As a result, most people have no symptoms. However, a person with a lipoma can have some pain if the lipoma presses on the nerves.
How are lipomas diagnosed?
In most cases, doctors can diagnose a lipoma with a simple physical examination. However, if the lipoma is large and/or painful, the doctor may order a test to confirm that the lump is not cancerous. These tests may include a biopsy, computed tomography (CT scan), or magnetic resonance imaging (MRI).
A biopsy is a procedure in which a small piece of the fatty tissue is removed from the lipoma so it can be examined under a microscope for signs of cancer. An MRI uses a magnet, radio waves, and a computer to take a series of very clear, detailed pictures. Like an MRI, a CT scan (or CAT scan) is a procedure that makes a series of detailed pictures, taken from different angles.
Once a lipoma is diagnosed, your doctor will discuss whether treatment is needed and what the options are.
How are lipomas treated?
In many cases, lipomas do not need to be treated. Instead, your doctor may simply recommend watching the lipoma on a regular basis. Sometimes a patient may elect to have the lipoma removed if he or she is concerned about its location and how it affects his or her appearance.
Occasionally, a lipoma causes pain or affects muscle development and needs to be removed. Lipomas are usually self-contained, meaning they do not invade the surrounding tissue. Therefore, it is usually possible for the doctor to make a small incision (cut) in the skin and then either squeeze out the lipoma, or use liposuction.
During the liposuction procedure, an incision is made in the lipoma, and a thin, hollow tube called a cannula is inserted into the incision. The cannula is then moved back and forth to loosen the fat, which is vacuumed up through the tube.
Liposuction can be useful for larger lipomas, but the procedure is associated with a higher rate of recurrence (growing back). Procedures to remove lipomas are usually done under local anesthesia, and patients go home the same day.
In cases where doctors are uncertain that the lump is simply a lipoma, it will need to be evaluated to ensure that it is not cancerous before being treated. This is because the procedures for removing lipomas can actually cause the cancer to spread. If it turns out that the lump is cancerous, your doctor will discuss different treatment options to remove the tumor.
What is the outlook for people with lipomas?
The outlook for people with lipomas is extremely positive. Because lipomas are generally harmless and cause no discomfort, they do not affect a person’s quality of life. Lipomas do not increase the risk of other diseases, and people who choose to have their lipomas removed for cosmetic reasons rarely have visible scarring.
- UpToDate. Overview of benign lesions of the skin. www.uptodate.com Accessed 3/8/2012
- American Academy of Family Physicians. Luba, Mark, et al, “Common Benign Skin Tumors.” American Family Physician, February 2003; pages 729-738. www.aafp.org Accessed 3/8/2012
- American Academy of Family Physicians. Salam, Gohar A., “Lipoma Excision.” American Family Physician, March 2002; pages 901-905.www.aafp.org Accessed 3/8/2012
- Liposuction procedure. American Society of Plastic Surgeons. www.plasticsurgery.org Accessed 3/8/2012
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 3/18/2012...#15008