A lipoma is a benign (noncancerous) tumor made up of fat tissue. Lipomas are found most often on the torso, neck, upper thighs, upper arms, and armpits, but they can occur almost anywhere in the body. Lipomas can occur in people of all ages, however, they tend to develop in adulthood and are most noticeable during middle age. They affect both sexes equally, although solitary lipomas are more common in women whilst multiple lipomas occur more frequently in men.
Causes of Lipoma
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.
Types of Lipoma
While all lipomas are made up of fat, there are sub-types based on the way they appear under the microscope. Some varieties include:
- Conventional lipoma (common, mature white fat)
- Hibernoma (brown fat instead of the usual white fat)
- Fibrolipoma (fat plus fibrous tissue)
- Angiolipoma (fat plus a large amount of blood vessels)
- Myelolipoma (fat plus tissue that makes blood cells)
- Spindle cell lipoma (fat with cells that look like rods)
- Pleomorphic lipoma (fat with cells of all different shapes and sizes)
- Atypical lipoma (deeper fat with a larger number of cells)
Signs and Symptoms of Lipoma
- 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.
Treatment of Lipoma
Lipomas do not generally require treatment. Because lipomas are not cancerous growths and cannot become cancerous, they do not need to be removed. There is no known treatment to prevent lipomas or affect their growth. Several methods are available:
- Simple surgical excision
- Squeeze technique (a small incision is made over the lipoma and the fatty tissue is squeezed through the hole)