A lipoma is a noncancerous, benign growth of fat cells that typically develops just below the skin. Lipomas can occur anywhere on the body, but are most commonly found on the neck, back, shoulders, and arms.

Lipomas are generally small, soft, and movable and are often painless, although they can sometimes grow quite large and cause discomfort or affect mobility if they are in a particularly sensitive area. They typically develop slowly over a period of months or years.

The exact cause of lipomas is not known, but they are thought to be genetic in nature, and they may occur more frequently in some families. They are also more common in people who are overweight or obese.

Lipomas are usually diagnosed based on their appearance and location, and often require no treatment. However, if a lipoma is causing discomfort or affecting movement, or if there is a concern that it may be a cancerous growth, a doctor may recommend removing it surgically.

While lipomas are generally harmless and do not require medical attention, any new growth or lump should be evaluated by a healthcare provider to rule out the possibility of a more serious condition.

The cause of lipomas isn't fully understood. They tend to run in families, so genetic factors likely play a role in their development.

No treatment is usually necessary for a lipoma. However, if the lipoma bothers you, is painful or is growing, your doctor might recommend that it be removed. Lipoma treatments include:

• Surgical removal. Most lipomas are removed surgically by cutting them out. Recurrences after removal are uncommon. Possible side effects are scarring and bruising. A technique known as minimal excision extraction may result in less scarring.
• Liposuction. This treatment uses a needle and a large syringe to remove the fatty lump.