A Plain-English Introduction: What’s Inside A Xanthoma, Where It Shows Up On The Body, And What Each Location Can Tell Your Doctor
A xanthoma is a yellowish lump or patch made of fat-filled immune cells, called foam cells, in the skin or tendons. Xanthomas can appear on the eyelids, tendons, palms, elbows, knees or buttocks, and where and how they appear often points to a specific blood fat problem. The commonest kind is xanthelasma, on the eyelids.
A xanthoma is a deposit of fat-filled immune cells in the skin or tendons, usually yellow, orange or skin-colored. It isn’t cancer, but many types are signs of a lipid disorder: tendon lumps suggest inherited high cholesterol, crops of small bumps suggest very high triglycerides, and palm-crease patches suggest dysbetalipoproteinemia. Any xanthoma deserves a doctor’s check and blood tests.
Key Takeaways
- A xanthoma is a collection of fat-filled foam cells in skin or tendons.
- Xanthelasma, on the eyelids, is the most common type.
- Where a xanthoma appears often points to a particular lipid disorder.
- Tendon xanthomas are a sign of familial hypercholesterolemia.
- Eruptive xanthomas signal very high triglycerides and pancreatitis risk.
- Blood tests matter more than the lump; see a doctor for any xanthoma.
On This Page 18 sections
What Is Xanthoma?
A xanthoma is a yellowish lump, bump or patch made of fat-filled immune cells in the skin or tendons. It’s benign, but it’s often a visible sign of raised or unbalanced blood fats, so it’s worth a doctor’s check.
The word comes from Greek xanthos, yellow, and “-oma,” a growth or mass. Xanthelasma palpebrarum, on the eyelids, is the most common form of xanthoma.[1] Other forms appear on the tendons, palms, elbows, knees and buttocks, and vary from soft flat patches to firm lumps.
This page is an introduction. For the whole family in depth, see our xanthomas guide; for the exact definition, see xanthoma definition; and for a shorter overview, xanthoma.
What Is Inside A Xanthoma?
Foam cells: immune cells called macrophages that have swallowed so much fat they look foamy under the microscope. They gather in the skin or tendon, sometimes with some inflammation.
In eyelid xanthelasma, these lipid-laden macrophages collect in the reticular dermis, the deeper part of the skin, around small blood vessels.[1] The fat they contain is mainly cholesterol carried in from the blood, which is why xanthomas are so closely tied to blood fat levels. The yellow color comes from that fat showing through the skin. Our guide to xanthomatous lesions explains the term used for foamy, fat-filled tissue.
How Does A Xanthoma Form?
Fats leak out of blood vessels into the tissue, macrophages take them up, and when the fat keeps coming faster than it can be cleared, the overloaded cells collect into a visible deposit.
On the eyelids, blinking repeatedly squeezes the small vessels, and with age they become leakier, letting fats seep into the skin.[1] Elsewhere, very high blood fats, as in inherited hypercholesterolemia or severe hypertriglyceridemia, drive deposits in tendons and skin.[2] [5] That’s why the size and pattern of xanthomas often track how high and how long blood fats have been raised.
What Causes Xanthomas?
Mostly raised or unbalanced blood fats, either inherited or caused by another condition such as diabetes, an underactive thyroid, liver or kidney disease, or certain medicines. Some xanthomas occur with normal blood fats.
- Familial hypercholesterolemia. Inherited very high LDL, affecting about 1 in 250 to 1 in 500 people.[2]
- Dysbetalipoproteinemia. A lipoprotein disorder behind palmar and tuberous xanthomas.[4]
- Very high triglycerides. Often with uncontrolled diabetes, behind eruptive xanthomas.[5]
- Secondary causes. Diabetes, an underactive thyroid, primary biliary cholangitis, nephrotic syndrome, and retinoid or estrogen medicines.[1]
- Rare metabolic conditions. Such as cerebrotendinous xanthomatosis.[3]
- Blood protein disorders. Linked with widespread flat xanthomas in people with normal lipids.[6]
Our guide to the causes of xanthelasma covers the eyelid form in depth.
Are Xanthomas Dangerous?
The deposits themselves aren’t harmful, but what they signal can be. Some types point to inherited high cholesterol and early heart disease; others to triglycerides high enough to risk pancreatitis.
Without care, about half of men with familial hypercholesterolemia had a heart event by 50, and about 30% of women by 60,[2] which is why tendon xanthomas deserve prompt attention. Eruptive xanthomas come with triglycerides at a level that raises the risk of pancreatitis.[5] Even eyelid xanthelasma is linked with blood fat disorders in about half of people.[1] The good news is that these conditions are very manageable once found, so a xanthoma is often the clue that leads to protecting your heart and pancreas.
Who Gets Xanthomas?
Anyone with a lipid disorder can, but some groups stand out: people with inherited high cholesterol, people with uncontrolled diabetes or very high triglycerides, and, for eyelid xanthelasma, women in midlife.
Familial hypercholesterolemia affects about 1 in 250 to 1 in 500 people and runs in families.[2] Eyelid xanthelasma affects about 1.1% of women and 0.3% of men, most often between 35 and 55, and when it appears young an inherited lipid disorder is more likely.[1] Cerebrotendinous xanthomatosis often shows first as diarrhea in infancy or cataracts in childhood, with tendon xanthomas in the teens or twenties.[3] If xanthomas run in your family, your relatives may benefit from testing too.
Where On The Body Can Xanthomas Appear?
On the eyelids (xanthelasma), tendons such as the Achilles and those on the hands, the palm creases, elbows and knees, the buttocks and backs of the arms and legs, and anywhere as flat patches.
Location is one of the most useful clues a doctor has. Tendon lumps and eyelid plaques together suggest familial hypercholesterolemia;[2] palm-crease deposits point to dysbetalipoproteinemia;[4] crops of small bumps on the buttocks and limbs suggest very high triglycerides.[5] Our guides to skin xanthomas and xanthoma skin cover the skin forms.
What Is Xanthoma? A Guide By Location
| Where | Type | What It Looks Like | What It Can Signal |
|---|---|---|---|
| Eyelids | Xanthelasma | Soft, flat yellow plaques near the inner corners | Lipid disorder in about half; heart risk |
| Achilles, hands, elbows, knees | Tendon xanthoma | Firm lumps on tendons | Familial hypercholesterolemia; rarely cerebrotendinous xanthomatosis |
| Buttocks, shoulders, limbs | Eruptive xanthoma | Crops of small yellow-red bumps | Very high triglycerides; pancreatitis risk |
| Palm and finger creases | Palmar xanthoma | Yellow streaks in the creases | Dysbetalipoproteinemia |
| Elbows, knees | Tuberous xanthoma | Firm yellow-orange nodules | Dysbetalipoproteinemia, high cholesterol |
| Anywhere, often widespread | Plane xanthoma | Flat yellowish patches | Lipid or liver disorder; with normal lipids, a blood protein disorder |
What Is A Xanthoma On The Eyelid?
It’s xanthelasma: soft, yellow, flat or slightly raised plaques near the inner corners of the eyelids, often on both sides. It’s the most common xanthoma, and about half of people with it have a lipid disorder.
Xanthelasma affects about 1.1% of women and 0.3% of men, usually between 35 and 55.[1] Unlike most body xanthomas, it often occurs with normal blood fats, and the plaques rarely fade even when cholesterol is managed, so many people choose to remove them once the cause has been checked. Recurrence after removal is generally under 50%.[1] Our main xanthelasma guide and eyelid xanthomas cover it in full.
If your xanthomas are on the eyelids and your doctor has checked the cause, this is the cream we make for eyelid xanthelasma.
What Is A Tendon Xanthoma?
A firm lump on a tendon, most often the Achilles tendon or the tendons on the backs of the hands, elbows or knees. It’s a classic sign of familial hypercholesterolemia.
Familial hypercholesterolemia is inherited, with a 50% chance of passing to each child; without care, about half of affected men had a heart event by 50 and about 30% of women by 60. Statins are the first-line medicine.[2] Rarely, tendon xanthomas come from cerebrotendinous xanthomatosis, a metabolic condition that also causes childhood cataracts in about 75% of people and nerve problems later, and that responds well to early care.[3] Our guides to tendon xanthomas and Achilles tendon xanthoma explain more.
What Is An Eruptive Xanthoma?
Crops of small yellow-red bumps that appear suddenly, often on the buttocks, shoulders and limbs. They’re linked with triglycerides above about 1,000 mg/dL, a level that also raises the risk of pancreatitis.
Uncontrolled diabetes is a common driver of these very high triglycerides.[5] Eruptive xanthomas are a reason to see a doctor promptly, because bringing triglycerides down protects the pancreas. Our guide to eruptive xanthoma describes what to look for.
What Are Xanthomas On The Palms, Elbows And Knees?
Yellow streaks in the palm and finger creases are palmar xanthomas; firm yellow-orange nodules over the elbows and knees are tuberous xanthomas. Both are linked with dysbetalipoproteinemia, and palmar xanthomas fade once it’s managed.
Dysbetalipoproteinemia is a disorder of how the body processes cholesterol-carrying particles; palmar and tuberous xanthomas are its typical skin signs, and palmar ones fade once the condition is managed.[4] Our guides to palmar xanthoma and tuberous xanthoma go into each.
What Is A Plane (Flat) Xanthoma?
Flat, yellowish patches that can appear anywhere, sometimes widely. They can come with lipid or liver disorders, and when they’re widespread in someone with normal blood fats, they’ve been linked with a blood protein disorder called monoclonal gammopathy.
Diffuse normolipemic plane xanthoma and its link with monoclonal gammopathy has been described in the hematology literature, with care directed at the underlying blood disorder.[6] That’s why widespread flat patches with normal cholesterol need investigation. Our guide to plane xanthoma covers this type in detail.
How Is A Xanthoma Diagnosed?
Usually by its look and location, confirmed with blood tests. A biopsy is used if the type is unclear, and further tests, such as genetic or blood protein tests, depend on what’s found.
- Examination. Where the xanthomas are, how they feel, and whether tendons are thickened.
- History. Family heart disease or high cholesterol, diabetes, liver or kidney disease, medicines.
- Blood tests. A fasting lipid profile, liver, thyroid and kidney tests, and blood sugar.[1]
- Genetic testing. If familial hypercholesterolemia is suspected.[2]
- Biopsy. When the diagnosis is uncertain.[1]
Our guide on what xanthelasma indicates explains the blood results for the eyelid form.
How Are Xanthomas Managed?
Mainly by managing the cause: diet, activity, weight, not smoking and usually lipid-lowering medicine, plus care for any condition raising blood fats. Removal is mostly for eyelid xanthelasma or lumps that persist.
For familial hypercholesterolemia, statins are first-line.[2] For eruptive xanthomas, lowering triglycerides and controlling blood sugar come first.[5] Palmar xanthomas fade once dysbetalipoproteinemia is managed.[4] Eyelid xanthelasma is the exception: plaques rarely fade with lipid control alone, so they’re often removed.[1] Our guide to xanthoma care by type sets out each approach.
When Should You See A Doctor About A Xanthoma Quickly?
Promptly for sudden crops of bumps, which can mean dangerously high triglycerides, and for tummy pain with them; soon for tendon lumps, xanthomas in a child or young adult, or widespread flat patches. Routinely for eyelid xanthelasma.
- Urgent. Eruptive bumps with severe upper abdominal pain, which can signal pancreatitis.[5]
- Soon. Tendon lumps, or xanthomas appearing young, which can signal inherited high cholesterol.[2]
- Soon. Widespread flat patches with normal lipids.[6]
- Routine. Typical eyelid xanthelasma, for blood tests and a heart risk check.
Our guide on which doctor to see explains who does what.
What’s The Bottom Line On What Xanthoma Is?
A xanthoma is a deposit of fat-filled foam cells in the skin or tendons. Its location often points to a specific lipid disorder, so blood tests and a doctor’s check matter more than the lump itself. Eyelid xanthelasma is the most common type and the one most often removed.
See a doctor for any xanthoma. For eyelid plaques only, Xanthel® is a cosmetic cream made for xanthelasma removal at home, sold by Xanthelasma.com. You’ll find it in the box above, or read more about Xanthel® xanthelasma removal cream, and browse all our xanthelasma and xanthoma guides.
Common Questions About What Xanthoma Is
What Is A Xanthoma?
A yellowish lump, bump or patch made of fat-filled immune cells in the skin or tendons. It’s benign but often a sign of raised or unbalanced blood fats.
Is A Xanthoma Cancer?
No. It’s a benign deposit of foam cells, though some types signal conditions with real health risks, so see a doctor.
What Causes Xanthomas?
Mostly raised or unbalanced blood fats, inherited or caused by diabetes, an underactive thyroid, liver or kidney disease or certain medicines.
Is Xanthelasma A Type Of Xanthoma?
Yes. Xanthelasma, on the eyelids, is the most common type of xanthoma.
What Does A Tendon Xanthoma Mean?
It’s a classic sign of familial hypercholesterolemia, an inherited cause of very high LDL cholesterol that raises heart risk.
What Do Eruptive Xanthomas Mean?
They’re linked with triglycerides above about 1,000 mg/dL, which also raise the risk of pancreatitis, so see a doctor promptly.
Do Xanthomas Go Away?
Some do once the cause is managed; palmar xanthomas fade once dysbetalipoproteinemia is controlled. Eyelid xanthelasma rarely fades without removal.
Can A Cream Remove A Xanthoma?
Only eyelid xanthelasma. Xanthel is made for the eyelid type, not for tendon, eruptive, palmar or other body xanthomas.
Sources
- Blair K. Xanthelasma Palpebrarum. StatPearls, National Library of Medicine (NCBI Bookshelf), updated 2026.
- Ison HE, Clarke SL, Knowles JW. Familial Hypercholesterolemia. GeneReviews, National Library of Medicine (NCBI Bookshelf), revised 2025.
- Federico A, Gallus GN. Cerebrotendinous Xanthomatosis. GeneReviews, National Library of Medicine (NCBI Bookshelf), revised 2024.
- Javvaji A, Can AS, Sharma S. Dysbetalipoproteinemia. StatPearls, National Library of Medicine (NCBI Bookshelf), updated 2024.
- Mishra C, Tripathy K. Lipemia Retinalis. StatPearls, National Library of Medicine (NCBI Bookshelf), updated 2026.
- Szalat R, et al. Pathogenesis and treatment of xanthomatosis associated with monoclonal gammopathy. Blood, 2011.
