An Overview of Lipoma

Lipomas are mostly harmless growths that occur under the skin or, in rare cases, on or around organs. They’re made up of adipose (fat) tissue and surrounded by a thin capsule that’s usually not attached to any nearby muscle. They’re rarely painful. 

There’s still a lot we don’t know about why lipomas form, but there are certain things that increase the chances of one developing, including having a family history of lipomas, being obese, or having certain medical conditions. In most cases, no treatment is recommended. But they can be removed or diminished for cosmetic reasons or in cases where the lipomas are large, painful, or located in areas where they could negatively affect health or mobility. 

Symptoms

Lipomas are lumps that form under the skin. They’re soft, doughy, and mobile—you can easily push them around with a finger. They don’t usually hurt or affect your mobility unless they form in or around joints, blood vessels, or nerves. 

Most people (90-95%) with lipomas will only have one, but some can develop multiple. The masses are generally small, 2-3 centimeters wide, though “giant lipomas” can grow bigger than 10 centimeters.

The lumps typically occur in the upper part of the body where there is a lot of fatty tissue, such as on the head and neck, shoulders, chest, and back. In rare cases, the lumps can grow on muscles or internal organs, like the stomach or intestines.

Causes

We still don’t know why exactly lipomas form, but there are some things that can make them more likely, such as genetics, injuries, or certain medical conditions. 

Genetics

Genetics appears to play a fairly substantial role in a person’s risks of getting lipomas. In about two-thirds of cases, there are mutations, rearrangements, or deletions of genes or chromosomes, and some of the conditions associated with lipomas are genetic.  

Medical Conditions 

Certain medical conditions or events can also be associated with (or increase the chances of) lipomas. These include: 

• Trauma: Direct impact on a given area. Research shows experiencing a direct impact on an area of soft tissue—like being struck or landing hard on a particular area—could increase the chances of developing lipomas. 
• Diabetes mellitus: A chronic disorder characterized by unusually high blood sugar (or glucose) levels because the pancreas doesn’t make enough insulin. Diabetes can be associated with other diseases that are also linked to lipomas, such as Madelung's disease. 
• High cholesterol: Also called hyperlipidemia, high cholesterol is a medical condition where there’s an abnormally high amount of fats, or lipids, in the blood. Lipomas are more common in those with high cholesterol than in those whose cholesterol levels are in a healthy range.
• Obesity: When a person has accumulated a large amount of body fat. This can increase a person’s chances of developing lipomas, especially if they have other risk factors, too. 
• Multiple hereditary lipomatosis: A rare condition that is believed to be passed down through families and characterized by multiple lipomas involving the abdominal area, arms, or legs. 
• Gardner syndrome: A type of a rare condition known as familial adenomatous polyposis (FAP), where those affected develop polyps, tumors, and lipomas, among other signs and symptoms. Those with Gardner syndrome have a greater chance than others of developing FAP-related cancers, particularly in and around the colon.  
• Madelung’s disease: Also known as multiple symmetric lipomatosis, this rare condition is characterized by growths in the upper part of the body, such as the neck, arms, shoulders, and chest. It primarily affects middle-aged men of Mediterranean ancestry with a history of prolonged or substantial alcohol use.
• Adiposis dolorosa: A condition where the lipomas or folds of fatty tissue apply pressure to nerves and can be painful. It’s especially common in overweight or obese women between the ages of 35 and 50.

Other Risk Factors 

In addition to medical conditions and genetics, other risk factors can also increase a person’s chances of lipomas, including age and sex. Lipomas are most likely to appear between the ages of 40 and 60, and they’re slightly more common in men than women.

Diagnosis

Healthcare providers typically diagnose lipomas during a simple physical exam. They'll likely ask you about your medical history, including whether you have any close family members with a history of lipomas, and then take a look at the growth and feel how firm it is. That, alone, is usually enough for a practitioner to make their diagnosis.

Lipomas are benign (harmless) tumors, but they're still tumors, and in some cases, medical professionals might want to perform additional tests to rule out cancer. These tests could include: 

• Biopsy: It’s not routine, but a healthcare provider might want to test the tissue for cancerous cells. They do this by cutting out a small piece of the lipoma(s) to test the tissue for cancerous cells. This is frequently done after lipomas have already been surgically removed.
• Imaging tests: Imaging tests of the tumor, like an ultrasound, computerized tomography (CT) scan, or magnetic resonance imaging (MRI), can give practitioners a better idea of how deep the mass goes, what tissue is affected, and whether there are any signs of abnormal tissue that might indicate the tumor is potentially cancerous or could otherwise harm your health.

These tests are typically performed if the lipomas grow quickly, are painful or attached to underlying tissue, occur in a particularly dangerous location like in deep tissues, or they’re excessively big (ex. larger than 10 centimeters).

Treatment

There's no cure for lipomas, but there are treatments available to make them smaller or remove them entirely.

Because lipomas are generally painless and harmless, they often don’t require treatment unless the individual wants them removed for cosmetic reasons. For routine cases, healthcare providers might just want to keep an eye on the growths to make sure they don’t continue to grow too large or otherwise become problematic.

However, a practitioner might recommend treatment if the lipomas are at risk of hurting your health or quality of life. Some red flags that might lead a healthcare provider to recommend treatment for lipomas include if they are:

• Very large.
• Painful.
• Poorly positioned, for example, near a nerve or joint.
• Limiting mobility or causing weakness.

In instances where a healthcare provider and individual with lipomas want to move forward with treatment, there are some options available, including surgery, injections, and liposuction. 

Surgical Excision 

The most common way to treat lipomas is by removing them altogether through surgery. In addition to being a relatively simple procedure, surgically removing the tumors is also often the best way to keep them from growing back, so long as the entire mass — including the capsule surrounding it — is completely removed. 

This technique is generally only done while the lipomas are small, however, and when they aren't located in areas that could be dangerous to operate on. If the growth grows too large, it could start to encroach on nerves and blood vessels, making surgery trickier and more invasive.

Liposuction 

For multiple growths or larger lipomas (ex. those larger than 4 centimeters wide), liposuction can be used as an alternative—or in addition—to surgery. This process works by breaking down the fat into smaller pieces, and then using a machine to suck them out of the body. 

There are a few key benefits to liposuction over surgery. Namely, it can be a much simpler process for removing multiple lipomas and often results in a shorter scar (or fewer of them) because you can remove several growths through a single opening. Like surgery, it’s also fairly effective at preventing the growths from coming back or turning into something more dangerous—so long as all of the broken-down pieces of the lipomas are completely removed.

Injections 

While it's not as common as surgery or liposuction, injections can also be used to treat lipomas. How it works is healthcare providers inject medications directly into the lipomas to break them down or shrink them, which can make them easier to surgically remove or for the body to dispose of on its own.

The two primary injections are made up using sodium deoxycholate or steroids combined with isoproterenol. The compounds used in the injections effectively dissolve or shrink the fat tissue down, allowing the body's immune system to more easily attack and remove them.

While research shows that injections can, in fact, make the lumps smaller, it’s not always the most effective treatment option. Some studies show that injections could actually make lipomas larger or grow back even after they’ve been treated. They also can inadvertently affect other tissue (ex. muscles or tendons) or cause unpleasant—though often temporary—side effects like bruising, swelling at the injection sites, or a disruption in the way the body breaks down fats in the bloodstream. 

A Word From Verywell

Lipomas are generally harmless and don’t require treatment unless your healthcare provider recommends it, though they can be removed or diminished for cosmetic reasons. That said, you should talk to your practitioner about any lipomas that are growing rapidly, becoming painful, or affecting your ability to move freely. And if you discover any new lumps that have yet to be diagnosed, don't simply assume they are lipomas. Have them examined by a medical professional right away.