Definition of Xanthoma:

Xanthoma is a skin condition in which fat builds up under the surface of the skin.

Causes, incidence, and risk factors:

Xanthomas are common, particularly among older adults and people with high blood lipids.

Xanthomas vary in size. Some are very small, while others are bigger than 3 inches in diameter. They may appear anywhere on the body, but are most often seen on the elbows, joints, tendons, knees, hands, feet, or buttocks.

They may be a sign of a medical condition that involves an increase in blood lipids. Such conditions include:

• Certain cancers
• Diabetes
• Inherited metabolic disorders such as familial hypercholesterolemia
• Primary biliary cirrhosis

Xanthelasma palpebra, a common type of xanthoma that appears on the eyelids and may occur without any underlying medical condition, is not necessarily associated with elevated cholesterol or lipids.