What is a lipoma?
A lipoma is a soft lump of fat under the skin. They’re very common and are usually harmless. They are most likely to appear on the trunk and extremities, but can appear almost anywhere on the body.
Most lipomas don’t cause any symptoms and are considered benign (not dangerous or cancerous). If they are tender, they are most likely angiolipomas—benign (non-cancerous) collections of blood vessels and fat cells.
How does a lipoma feel?
Lipomas are soft and squishy. They are made up of fat tissue. Typically, lipomas feel like a swelling with no change in texture or color of the overlying skin. When pressed, a lipoma usually feels like a bump or nodule underneath the skin.
They are typically round, smooth, easily moveable, and painless. They can be as small as 1 cm or as big as 10 cm or more.
Most people develop lipomas on the neck, arm, leg, chest, or back. Sometimes they may appear on your hands, feet, or head.
Why do lipomas form?
Madelung disease (multiple symmetric lipomatosis) is a disorder of fat metabolism most commonly seen in middle aged males with a history of alcohol abuse. Patients develop large, disfiguring lipomas involving the neck and shoulders. —Dr. MacCormack
Doctors don’t know why people get lipomas. Most people who get lipomas are otherwise healthy. When you have many lipomas, especially if other family members have similar symptoms, it may be a sign of a genetic disorder called familial multiple lipomatosis.
Still, there are some risk factors that may make you more likely to develop them.
- Being overweight or obese
- High cholesterol
- Genetic conditions
Do lipomas go away?
Lipomas do not go away on their own. They typically grow to a certain size and then stabilize, but they may get bigger if you gain weight. Unfortunately, if you lose weight, they do not shrink. In fact, they may become more noticeable.
Sometimes the bumps are mistaken for cysts (called epidermal inclusion cysts). One main difference is that an epidermal inclusion cyst has a central dilated pore that you can see and may drain blood, keratin, or pus. Lipomas are also usually less firm and tender than cysts.
If you notice a bump under your skin, see your doctor. They may suggest making an appointment with a dermatologist (a doctor who specializes in skin diseases).
Usually, lipomas are diagnosed with a skin exam. Sometimes, the doctor will do an ultrasound. They may want to rule out that it isn’t something else by performing a biopsy.
Can a lipoma turn into cancer?
Usually, lipomas don’t turn into cancer. Removal is unnecessary unless the lesion is painful, rapidly growing or otherwise symptomatic.
Lipomas are easily removed in a surgical procedure. Typically it is performed with local anesthesia. Side effects of surgery include post-operative scar and other risks such as bleeding and infection. It may take several weeks for the skin to heal.
Lipomas have also been treated with liposuction (a fat removal procedure) and injection of medications to dissolve fat. However, these treatments are less commonly performed due to increased cost and decreased effectiveness.
If the lipoma is removed with surgery, your doctor will typically schedule a follow-up to remove the stitches.
If you have a genetic condition that causes many lipomas, you may need regular follow-up visits with your doctor.