Definition

A lipoma is a harmless lump of fat. There are several types, mainly classified by where they appear. The most common location is just beneath the skin, where they are easily felt. But, lipomas can occur anywhere.

Most tissue in the body can grow beyond its normal limits and form a lump or tumor. Tumors come in two forms:

• Benign—stop growing after they reach a certain size (eg, moles]]> , polyps, lipomas); some can turn into cancer, but lipomas do not
• Malignant—cancer, rarely stops growing

Benign Tumor

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Causes

Lipomas have no known cause.

Risk Factors

These factors increase your chance of developing lipomas. Tell your doctor if you have any of these risk factors:

• Family history—A tendency to grow lipomas seems to run in families.
• Lipomatosis—This is a hereditary condition that produces many lipomas all over the body.
• Adiposis dolorosa—This is a rare disease that produces many painful lipomas.
• Obesity]]>

Symptoms

If you have any of these symptoms do not assume it is due to lipomas. These symptoms may be caused by other conditions. Tell your doctor if you notice a soft lump under your skin. The lump may be:

• The size of a pea to a grapefruit
• Painless, but tender to touch
• Big enough or located in place that causes pain (eg, over a nerve)—This is rare.
• Painful and red if frequently irritated
• Frequently tender or painful (certain type of lipoma called angiolipoma)

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam. The diagnosis is usually based on the smoothness, softness, and ease of movement under the skin. If there is doubt, it will be biopsied]]> or imaged.

Treatment

Talk with your doctor about the best treatment plan for you. You may want to leave the lump alone. Although if it is growing rapidly, the lump should be biopsied. Treatment options include:

Prevention

There are no methods to prevent lipomas.