Topic Overview

What is a lipoma?

A lipoma is a growth of fat cells in a thin, fibrous capsule usually found just below the skin. Lipomas are found most often on the torso, neck, upper thighs, upper arms, and armpits, but they can occur almost anywhere in the body. One or more lipomas may be present at the same time. Lipomas are the most common noncancerous soft tissue growth.

What causes a lipoma?

The cause of lipomas is not completely understood, but the tendency to develop them is inherited. A minor injury may trigger the growth. Being overweight does not cause lipomas.

What are the symptoms of a lipoma?

Lipomas usually:

• Are small [0.4 in. (1 cm) to 1.2 in. (3 cm)] and felt just under the skin.
• Are movable and have a soft, rubbery consistency.
• Do not cause pain.
• Remain the same size over years or grow very slowly.

Often the most bothersome symptom is the location or increased size that makes the lipoma noticeable by others.

How are lipomas diagnosed?

A lipoma can usually be diagnosed by its appearance alone, but your health professional may want to remove it to make sure the growth is noncancerous.

How are lipomas treated?

Lipomas do not generally require treatment. Because lipomas are not cancerous growths and cannot become cancerous, they do not need to be removed. There is no known treatment to prevent lipomas or affect their growth.

A lipoma may be surgically removed if symptoms develop, such as if the lipoma:

• Becomes painful or tender.
• Becomes infected or inflamed repeatedly.
• Drains foul-smelling discharge.
• Interferes with movement or function.
• Increases in size.
• Becomes unsightly or bothersome.

Most lipomas can be removed in the doctor's office or outpatient surgery center. The doctor injects a local anesthetic around the lipoma, makes an incision in the skin, removes the growth, and closes the incision with stitches (sutures). If the lipoma is in an area of the body that cannot be easily reached through a simple incision in the skin, the lipoma may need to be removed in the operating room under general anesthesia.

Who is affected by lipomas?

Lipomas occur in all age groups but most often appear in middle age. Single lipomas occur with equal frequency in men and women. Multiple lipomas occur more frequently in men.