Plane Xanthoma

What Is Plane Xanthoma?

Plane xanthoma is a type of xanthoma that forms flat or very slightly raised yellow patches in the skin, rather than lumps or bumps. The patches are made of immune cells that have filled up with fat.

Xanthomas are deposits of fat in the skin or tendons, and doctors group them by shape and location. “Plane” simply means flat. Instead of forming firm nodules like tuberous or tendon xanthomas, plane xanthomas spread out as soft yellow or orange patches that sit level with the skin or just above it.

The most familiar plane xanthoma is xanthelasma, the soft yellow plaques on the eyelids. It’s also the most common type of xanthoma overall, affecting around 1.1% of women and 0.3% of men.^[1] Other plane xanthomas are much rarer and can appear on the palms, neck, trunk and skin folds. Our xanthomas guide covers the whole family, and the main xanthelasma page covers the eyelid form.

What Does Plane Xanthoma Look Like, And Where Does It Appear?

Plane xanthomas are flat, yellow to orange patches with soft edges. They can appear on the eyelids, in the creases of the palms, or spread across the neck, upper chest, back and skin folds such as the armpits and groin.

Plane xanthomas are usually painless and don’t itch, which is one reason they can go unnoticed for a while. They often look like a stain in the skin rather than a lump, and their color comes from the fat stored in the skin cells. Depending on the type, they may be:

• On the eyelids. Soft yellow plaques near the inner corner, usually on both sides: this is xanthelasma.
• In the palm creases. Yellow lines following the natural folds of the palms and fingers.
• Spread across the skin. Larger, symmetrical patches on the neck, upper trunk, shoulders or in skin folds.

Because several conditions can look similar, a doctor or dermatologist should confirm what any flat yellow patch actually is. Our guide to what can look like xanthelasma covers the common lookalikes, and skin xanthomas covers xanthomas on the body more broadly.

What Are The Types Of Plane Xanthoma?

The main types are xanthelasma on the eyelids, palmar xanthomas in the palm creases, and diffuse plane xanthomas spread across the body, which often occur with normal cholesterol.

The type matters, because each tends to point in a different direction. Xanthelasma is often cosmetic, though about half of people with it have a lipid disorder.^[1] Palmar xanthomas in the creases of the palms are seen in an inherited lipid disorder called dysbetalipoproteinemia, and they tend to fade once it’s managed.^[5] Diffuse plane xanthomas with normal blood fats have been reported alongside blood protein disorders.^[2][3]

Each has more on our site: palmar xanthoma, eyelid xanthomas and xanthomatosis, the term for widespread xanthomas.

What Causes Plane Xanthoma?

Plane xanthomas form when immune cells in the skin fill with fat and become “foam cells”. That can be driven by raised blood fats, or, in the diffuse normolipemic type, by abnormal blood proteins that carry fats into the skin.

Every xanthoma has the same basic building block: macrophages, the immune cells that tidy up the body, take in more fat than they can process and swell into fat-filled foam cells. Where they gather, a yellow patch forms. What differs is why the fat ends up there.

In types linked to lipid disorders, it’s simply too much fat in the blood. In diffuse normolipemic plane xanthoma, blood fats are normal, so researchers have looked for another explanation. The leading theory is that an abnormal antibody protein, made in excess in conditions such as monoclonal gammopathy, binds to fat-carrying particles in the blood. These clumps settle in the skin, where macrophages swallow them and turn into foam cells.^[2][3] That’s why this type is taken seriously. For how fats build up in eyelid skin specifically, see our guide to the causes of xanthelasma.

Is Plane Xanthoma Linked To Blood Disorders?

Some types are. Diffuse plane xanthomas, especially with normal cholesterol, have been linked to monoclonal gammopathy, and in some reported cases the skin patches were the first sign of multiple myeloma.

Monoclonal gammopathy means the blood contains an unusual amount of a single antibody protein, made by one group of plasma cells. Often it’s a mild, stable finding called MGUS (monoclonal gammopathy of undetermined significance) that simply needs monitoring. Sometimes it’s part of a blood cancer such as multiple myeloma.

Read moreWho Removes Xanthelasma

Doctors have reported diffuse plane xanthomas alongside monoclonal gammopathy many times,^[2][3] One recent report describes a patient with normal cholesterol whose symmetrical yellow plaques covered the eyelids, neck, armpits, upper back and thighs; tests found a monoclonal protein and the mild MGUS form, and the authors advise ongoing monitoring because these patches can appear years before any wider illness.^[3] There are also cases where the yellow patches appeared before the blood condition was found and were the first manifestation of multiple myeloma.^[4] That’s the main reason plane xanthomas beyond the eyelids should never be dismissed as just a cosmetic issue.

It’s important to keep this in proportion. These are uncommon conditions, and ordinary xanthelasma on the eyelids isn’t known to carry this link. Checking is about catching anything early, not assuming the worst.

How Is Plane Xanthoma Diagnosed?

A dermatologist examines the patches and usually confirms plane xanthoma with a small skin biopsy, then arranges blood tests for cholesterol and, for widespread patches, a check for abnormal blood proteins.

Diagnosis has two parts: confirming what the patches are, and finding out why they’re there. A typical route looks like this:

1. Examination and history. The doctor looks at where the patches are, how long they’ve been there, and asks about family history and other symptoms.
2. Skin biopsy. A small sample, taken under local anesthetic, shows the fat-filled foam cells and rules out lookalikes.
3. Lipid panel. Measures cholesterol and triglycerides, to see whether a lipid disorder is involved.
4. Blood protein tests. For widespread patches, especially with normal lipids, tests such as serum protein electrophoresis look for a monoclonal protein, alongside a blood count, kidney function and calcium.
5. Specialist referral if needed. If a monoclonal protein is found, a hematologist decides whether further tests, such as scans or a bone marrow sample, are needed.

For eyelid-only xanthelasma, the checks are usually simpler: a lipid panel plus blood sugar and thyroid tests.^[1]

How Is Plane Xanthoma Different From Xanthelasma?

Xanthelasma is the eyelid form of plane xanthoma and is usually a cosmetic concern. Plane xanthomas elsewhere on the body are rarer, more widespread and more likely to need a medical workup.

The simplest rule: yellow patches only on your eyelids are very likely xanthelasma, while flat yellow patches anywhere else, or spreading beyond the eyelids, need to be seen by a doctor before anything else. Tuberous and tendon xanthomas are different again, forming firm lumps rather than flat patches; see tuberous xanthoma and tendon xanthomas.

Is Plane Xanthoma Dangerous?

The patches themselves aren’t harmful. What matters is what they might point to, which is why widespread plane xanthomas should be investigated rather than ignored.

Plane xanthomas don’t hurt, aren’t contagious and don’t turn into cancer. In that sense, they’re harmless. But they can be a signal: of a lipid disorder that affects heart health, or, in the diffuse normolipemic type, of a blood protein condition that needs monitoring.

For most people the investigations are reassuring or find something manageable. Even when a monoclonal gammopathy is found, it’s often the mild MGUS form, which is watched with regular blood tests rather than needing anything more. The value of the checks is that anything important is found early. Our page on whether xanthelasma is dangerous covers the eyelid form, which is usually much simpler.

How Is Plane Xanthoma Managed?

By dealing with the cause first: managing any lipid disorder, and monitoring or managing any blood protein condition with a specialist. The patches themselves can sometimes be removed afterwards if they bother you.

Management depends entirely on the type. Where a lipid disorder is behind it, diet, activity and cholesterol-lowering medicine come first, and some plane xanthomas, such as palmar ones, fade as blood fats improve.^[5] Where a blood protein disorder is involved, a hematologist leads, and the skin is a secondary concern. If patches remain and bother you, a dermatologist can discuss removing them, weighing up the risk of scarring.

Eyelid xanthelasma is different. Once a doctor has confirmed that’s what you have and checked your bloods, it’s usually a cosmetic matter, and it can be removed at a clinic or at home. Our guides to the removal of xanthelasma and xanthelasma cream compare the options.

If a doctor has confirmed that the yellow patches on your eyelids are ordinary xanthelasma, this is the at-home cream we make for them.

When Should You See A Doctor About Plane Xanthoma?

Read moreIs Xanthelasma Dangerous

Always, for any flat yellow patches beyond the eyelids. For eyelid patches, one visit for a cholesterol check is enough before you decide whether to remove them.

A GP or family doctor is the right first step; they’ll refer you to a dermatologist or hematologist if needed. If xanthomas appear across large areas of the body, our page on xanthoma disseminatum covers another rare widespread form.

What’s The Bottom Line On Plane Xanthoma?

Plane xanthoma is a flat yellow fat deposit in the skin; on the eyelids it’s usually harmless xanthelasma, but widespread patches elsewhere need a doctor’s check for lipid or blood protein disorders.

If your patches are only on your eyelids, have a cholesterol check, then decide whether to remove them. If they’re anywhere else, or spreading, see your doctor first and let them guide the next steps. Xanthel® is a cosmetic cream made for xanthelasma removal at home, sold by Xanthelasma.com, for the eyelid form only. You’ll find it at the foot of this page, or read more about Xanthel® xanthelasma removal cream and browse our other xanthelasma guides.

Common Questions About Plane Xanthoma

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