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, and ultrasound scan (USS), computed tomography (CT scan), or magnetic resonance imaging (MRI). 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 remove a lipoma.

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 tumour.