A xanthoma (pl. xanthomas or xanthomata) (condition: xanthomatosis) is a deposition of yellowish
cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
-rich material that can appear anywhere in the body in various disease states.
They are cutaneous manifestations of
lipidosis in which
lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...
s accumulate in large
foam cell
Foam cells, also called lipid-laden macrophages, are a type of cell that contain cholesterol. These can form a plaque that can lead to atherosclerosis and trigger heart attacks and stroke.
Foam cells are fat-laden cells with a M2 macrophage-like ...
s within the skin.
They are associated with
hyperlipidemia
Hyperlipidemia is abnormally elevated levels of any or all lipids (fats, cholesterol, or triglycerides) or lipoproteins in the blood. citing: and The term ''hyperlipidemia'' refers to the laboratory finding itself and is also used as an umbre ...
s, both primary and secondary types.
Tendon xanthomas are associated with type II hyperlipidemia, chronic
biliary tract obstruction,
primary biliary cirrhosis
Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build ...
,
sitosterolemia
Sitosterolemia is a rare autosomal recessively inherited lipid metabolic disorder. It is characterized by hyperabsorption and decreased biliary excretion of dietary sterols (including the plant phytosterol beta-sitosterol). Healthy persons absorb ...
and the rare metabolic disease
cerebrotendineous xanthomatosis
Cerebrotendinous xanthomatosis, also called cerebral cholesterosis, is an autosomal recessive form of xanthomatosis. It falls within a group of genetic disorders called the leukodystrophies.
Presentation
An inherited disorder associated with the ...
. Palmar xanthomata and tuberoeruptive xanthomata (over knees and elbows) occur in type III hyperlipidemia.
Etymology
The term xanthoma stems from Greek ξανθός (xanthós) 'yellow', and -ωμα -oma, a suffix forming nouns indicating a mass or tumor.
Types
Xanthelasma
![Xanthoma histology](https://upload.wikimedia.org/wikipedia/commons/c/c8/Xanthoma_histology.jpg)
A
xanthelasma
Xanthelasma is a sharply demarcated yellowish deposit of cholesterol underneath the skin. It usually occurs on or around the eyelids (''xanthelasma palpebrarum'', abbreviated XP). While they are neither harmful to the skin nor painful, these mino ...
is a sharply demarcated yellowish collection of cholesterol underneath the skin, usually on or around the
eyelids
An eyelid is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. The human eye ...
. Strictly, a xanthelasma is a distinct condition, being called a xanthoma only when becoming larger and nodular, assuming tumorous proportions. Still, it is often classified simply as a subtype of xanthoma.
Xanthoma tuberosum
Xanthoma tuberosum (also known as tuberous xanthoma) is characterized by xanthomas located over tuberosity of the joints.
Xanthoma tendinosum
Xanthoma tendinosum (also tendon xanthoma or tendinous xanthoma
) is clinically characterized by
papule
A papule is a small, well-defined bump in the skin. It may have a rounded, pointed or flat top, and may have a dip. It can appear with a stalk, be thread-like or look warty. It can be soft or firm and its surface may be rough or smooth. Some h ...
s and nodules found in the tendons of the hands, feet, and heel.
Also associated with
familial hypercholesterolemia
Familial hypercholesterolemia (FH) is a genetic disorder characterized by high cholesterol levels, specifically very high levels of low-density lipoprotein (LDL cholesterol), in the blood and early cardiovascular disease. The most common mutatio ...
(FH).
Eruptive xanthoma
Eruptive xanthoma (
ILDS
The International League of Dermatological Societies (ILDS) is a non-governmental organization that works closely with the World Health Organization. It was founded in 1935, but because of World War II no congresses were held until 1952. It is gov ...
E78.220) is clinically characterized by small, yellowish-orange to reddish-brown
papule
A papule is a small, well-defined bump in the skin. It may have a rounded, pointed or flat top, and may have a dip. It can appear with a stalk, be thread-like or look warty. It can be soft or firm and its surface may be rough or smooth. Some h ...
s surrounded by an
erythematous
Erythema (from the Greek , meaning red) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not assoc ...
halo that appear suddenly all over the body, especially the hands, buttocks, and the extensor surfaces of the extremities.
It tends to be associated with elevated triglycerides.
Xanthoma planum
Xanthoma planum (
ILDS
The International League of Dermatological Societies (ILDS) is a non-governmental organization that works closely with the World Health Organization. It was founded in 1935, but because of World War II no congresses were held until 1952. It is gov ...
D76.370), also known as plane xanthoma, is clinically characterized by bands or rectangular plates (
macule
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this sy ...
s) and plaques in the dermis spread diffusely over large areas of the body.
Palmar xanthoma
Palmar xanthoma is clinically characterized by yellowish plaques that involve the palms and flexural surfaces of the fingers.
Plane xanthomas are characterised by yellowish to orange, flat macules or slightly elevated plaques, often with a central white area which may be localised or generalised. They often arise in the skin folds, especially the palmar creases. They occur in hyperlipoproteinaemia type III and type IIA, and in association with biliary cirrhosis. The presence of palmar xanthomata, like the presence of tendinous xanthomata, is indicative of hypercholesterolaemia.
Tuberoeruptive xanthoma
Tuberoeruptive xanthoma (
ILDS
The International League of Dermatological Societies (ILDS) is a non-governmental organization that works closely with the World Health Organization. It was founded in 1935, but because of World War II no congresses were held until 1952. It is gov ...
E78.210) is clinically characterized by red papules and nodules that appear inflamed and tend to coalesce.
Tuberous xanthomata are considered similar, and within the same disease spectrum as eruptive xanthomata.
Other types
Other types of xanthoma identified in the Medical Dictionary include:
*
Xanthoma diabeticorum: a type of eruptive xanthoma, often with severe
diabetes
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...
.
*
Xanthoma disseminatum
Xanthoma disseminatum is a rare cutaneous condition that preferentially affects males in childhood, characterized by the insidious onset of small, yellow-red to brown papules and nodules that are discrete and disseminated.
It is a histiocytosis sy ...
: a rare xanthoma consisting of
non-X histiocytes on flexural (folded) surfaces, associated with
diabetes insipidus
Diabetes insipidus (DI), recently renamed to Arginine Vasopressin Deficiency (AVP-D) and Arginine Vasopressin Resistance (AVP-R), is a condition characterized by large amounts of dilute urine and increased thirst. The amount of urine produce ...
.
* Verrucous xanthoma, or
histiocytosis
In medicine, histiocytosis is an excessive number of histiocytes (tissue macrophages), and the term is also often used to refer to a group of rare diseases which share this sign as a characteristic. Occasionally and confusingly, the term "histioc ...
Y: a
papilloma
A papilloma (plural papillomas or papillomata) ('' papillo-'' + '' -oma'') is a benign epithelial tumor growing exophytically (outwardly projecting) in nipple-like and often finger-like fronds. In this context, papilla refers to the projection cre ...
of the
oral mucosa
The oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed ''lamina propria''. The oral cavity has sometimes been descri ...
and skin whereby the connective tissue under the epithelium contains
histiocytes
A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system). The mononuclear phagocytic system is part of the organism's immune system. The histiocyt ...
.
See also
*
Xanthelasma
Xanthelasma is a sharply demarcated yellowish deposit of cholesterol underneath the skin. It usually occurs on or around the eyelids (''xanthelasma palpebrarum'', abbreviated XP). While they are neither harmful to the skin nor painful, these mino ...
*
References
External links
*
*
{{Lipidemias
Medical signs
Hepatology
Skin conditions resulting from errors in metabolism