A lipoma is a slow-growing, fatty lump of harmless mass that is not cancer and most often situated between your skin and the underlying muscle layer. Usually, detected in middle age, lipomas can feel doughy and usually isn't tender, moves easily with slight finger pressure. Some people have more than one lipoma.
Lipomas can occur anywhere in the body such as:
- Under the skin - especially in the neck, shoulders, back, abdomen, arms and thighs.
- Soft and doughy to the touch - moves easily with slight finger pressure.
- Generally small - typically less than 2 inches (5 centimeters) in diameter, but they can grow.
- Sometimes painful - Lipomas can be painful when they grow and press on nearby nerves or if they contain many blood vessels.
- Exceptions - some lipomas can be deeper and larger than the usual lipomas.
The following factors may increase the risk of developing a lipoma:
- Age between 40 and 60 years old - Lipomas can occur at any age but they're most common in this age group and are rare in children.
- Having certain other disorders - People with other disorders like adiposis dolorosa, Cowden syndrome and Gardner's syndrome have an increased risk of multiple lipomas.
- Genetics - Lipomas tend to run in families.
The doctor will perform the following to diagnose a lipoma:
- A physical examination
- Biopsy which is a tissue sample for lab examination
- An ultrasound or other imaging tests like an MRI or CT scan, if the lipoma is large and has unusual features or appears to be deeper than the fatty tissue
It is unusual for lipoma to be cancerous , when it is called a liposarcoma. Liposarcomas are cancerous tumors in fatty tissues which grow rapidly, don't easily move under the skin and are usually painful. A biopsy, MRI or CT scan is typically done if the doctor suspects liposarcoma.
Lipomas usually do not require treatment. However, the doctor will recommend removal of the lipoma only if the lipoma is painful or is growing. Lipoma treatments include:
- Surgical removal - Most lipomas are removed surgically by cutting them out. Relapse after removal is uncommon. Possible side effects are scarring and bruising.
- Steroid injections - This treatment shrinks the lipoma but usually doesn't eliminate it. The use and potential of injections before surgical removal is still being studied.
- Liposuction - In this treatment, a needle and a large syringe are used to remove the fatty lump.