Conditions Basics

What is a lipoma?

A lipoma is a growth of fat cells in a thin, fibrous capsule usually found just below the skin. Lipomas aren't cancer and don't turn into cancer. They 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.

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.

What causes it?

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?

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 is it diagnosed?

A lipoma can usually be diagnosed by its appearance alone. In some cases, your doctor may order an imaging test, such as an ultrasound. Based on the results of the imaging test, your doctor may want to remove it to make sure the growth is noncancerous.

How is a lipoma treated?

Lipomas usually are not treated, because most of them don't hurt or cause problems. Your doctor might remove the lipoma if it is painful, gets infected, or bothers you.

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.