Xanthoma: Causes, Types, Clinical Features, Diagnosis, and Treatment

What Is Xanthoma?

Xanthoma is a type of condition that involves the buildup of fat under the surface of the skin. This is caused by the high levels of lipids or fats in the blood. The buildup of fats under the skin leads to growth (bumps), which can appear anywhere on the body. They can vary in size and can also develop in the internal organs of the body.

What Is the Epidemiology of Xanthoma?

Xanthomas result from irregular lipid metabolism or hyperlipidemia (high levels of fat or lipids) in the blood. Xanthomas usually affects adults, with equal prevalence reported in males and females.

What Are the Causes of Xanthoma?

Xanthomas are commonly seen among older adults with high levels of blood lipids. Xanthomas can vary in size, some are very small, and some are bigger than three inches in diameter. Xanthomas may be seen in any of the following medical conditions which include -

• Hyperlipidemia (high level of lipids in the blood).

• Diabetes.

• Certain cancers.

• Elevated blood cholesterol levels.

• Inherited metabolic disorders, such as familial hypercholesterolemia.

• Scarring of the liver due to damaged bile ducts (primary biliary cirrhosis).

• Inflammation and swelling of the pancreas (pancreatitis).

• Underactive thyroid (hypothyroidism).

• Xanthelasma palpebra (a common type of xanthoma that appears on the eyelids).

What Are the Clinical Features of Xanthoma?

Xanthomas appear as small bumps on the skin, which are generally small. They might appear as a single bump or in clusters, or a large group can occur at once. Usually, they do not have a uniform shape and size, and their color might vary from reddish to yellowish. These bumps usually do not have any symptoms but can be itchy or tender to the touch. These bumps or lesions can appear anywhere on the body but are mostly found on the -

• Elbows.

• Joints.

• Tendons.

• Knees.

• Hands.

• Feet.

• Buttocks.

What Are the Types of Xanthomas?

There are multiple types of xanthomas, which are classified according to their clinical presentation -

1. Xanthelasma:

Xanthelasma, also known as xanthelasma palpebrarum or xanthelasma palpebrum, is the most common type of xanthoma. This is usually present around the medial canthus of the upper eyelid. Some of the clinical features of this type include the following-

• It starts as a small bump that gains size over several months.

• Presents as soft, yellow, or yellow-orange macules, papules, or plaques.

• It can even occur with the normal levels of lipids in the blood.

2. Plane Xanthomas:

Also known as planar xanthoma or plane xanthomatosis. These soft, yellow macules or patches can occur anywhere on the body. Plane xanthomas are also associated with Type III hyperlipoproteinemia (characterized by elevated levels of total cholesterol and triglycerides) and must be distinguished from diffuse plane xanthomatosis.

3. Palmar Xanthoma:

Also known as xanthoma striata palmaris, presents as a yellow-orange overgrowth in the regions of the palm and wrist.

4. Tuberous Xanthoma:

Tuberous xanthomas are usually firm, painless, red-yellow nodules that develop over pressure areas such as the knees, elbows, and heels. They are also associated with Type III hyperlipoproteinemia and may join to form large multilobulated masses.

5. Tendon Xanthomas:

These are slowly enlarging subcutaneous nodules that are smooth, firm to palpation, and mobile. They are usually attached to the Achilles tendon over the knuckles. No skin color change is present, and it is most commonly associated with familial hypercholesterolemia (a genetic disorder in which the body cannot remove low-density lipoprotein or cholesterol, resulting in a high LDL level in the blood).

6. Eruptive Xanthoma:

This type of xanthoma usually appears as a yellow papule with a red rim of two to five millimeters. They are generally present on surfaces like the buttocks or shoulders but can be found on some other areas of the body, like the mouth, and can be tender or itchy.

7. Verruciform Xanthoma:

This is a rare type of xanthoma that commonly affects the mouth, where it is found as a solitary and asymptomatic lesion on the gingiva. If it is present on the gingiva, it is called a Vegas (verruciform genital-associated) xanthoma and appears as a yellow-brown or red verrucous plaque.

What Are the Complications of Xanthoma?

Increased lipid levels in the blood usually cause xanthoma. Therefore, the complications involved with this condition include pancreatitis or cardiovascular disease like ischemic heart disease.

How Is Xanthoma Diagnosed?

To diagnose xanthoma, the healthcare provider will examine the skin first, and usually, in most cases, the diagnosis is made by only looking at the xanthoma. If required, the healthcare provider will remove a sample of the growth for biopsy, which will help identify whether the lesion is cancerous. Other than that, some of the following investigations can also be done such as -

Cholesterol Tests- The doctor might order a blood test to check blood lipids such as cholesterol and triglyceride levels. In addition, some more blood tests may also be required to check for irregularities that might indicate diabetes, liver disease, pancreatitis, or thyroid problems.

What Is the Treatment for Xanthoma?

Some types of xanthomas can be treated by treating the underlying cause (hyperlipidemia), such as tuberous, eruptive, plane, and palmar xanthomas. Although the treatment of the growth on the skin is required for cosmetic reasons, it can be done by following procedures such as -

• Electrodesiccation (a simple technique in which an electrical current is used to remove specific skin lesions such as skin tags or brown spots).

• Cryotherapy (in this technique, extreme cold is used to freeze and remove abnormal tissue).

• Laser vaporization (Nd: YAG, Er: YAG, or carbon dioxide laser is used to destroy cells or lesions).

• Excision.

A verrucous xanthoma that appears in the oral cavity can be treated by surgical excision and rarely recurs.

What Is the Differential Diagnosis for Xanthoma?

Xanthomas might be needed to distinguish from many other skin lesions, such as

• Tuberous and tendon xanthomas are confused with rheumatoid nodules (firm lumps under the skin in patients with rheumatoid arthritis).

• Verruciform xanthoma can resemble a genital wart.

• Plane xanthomas need to be distinguished from eruptive and plane xanthomas.

Conclusion:

Xanthomas are noncancerous and painless growths that may indicate an underlying medical condition. Therefore, the prognosis of this condition depends upon the successful management of the underlying cause. However, it is still advised to the patient to maintain appropriate blood lipid and cholesterol levels by eating healthy foods and exercising regularly to prevent such conditions.