A lipoma is a slow-growing, noncancerous, fatty lump of overgrown fat cells that most often sits between the skin and muscle layer. They are generally soft to touch, slow growing, colorless and situated just under the skin. A lipoma is rarely a serious medical condition, but any lump needs to be examined by a doctor. People suffering with multiple lipomas have often inherited a gene from their parents that causes growth of one or more fatty tumors. Lipomas can occur more frequently in people with Gardner’s and Cowden syndrome, Madelung’s disease and adiposis dolorosa. Other risk factors include obesity, high cholesterol, diabetes and liver disease. Learn more about lipomas.