Touton giant cells are a type of multinucleated giant cell seen in lesions with high lipid content such as fat necrosis, xanthoma, and xanthelasma and xanthogranulomas.They are also found in dermatofibroma.
Touton giant cells are named for Karl Touton, a German botanist and dermatologist.Karl Touton first observed these cells in 1885 and named them "xanthelasmatic giant cells", a name which has since fallen out of favor.
Touton giant cells, being multinucleated giant cells, can be distinguished by the presence of several nuclei in a distinct pattern. They contain a ring of nuclei surrounding a central homogeneous cytoplasm, while foamy cytoplasm surrounds the nuclei.The cytoplasm surrounded by the nuclei has been described as both amphophilic and eosinophilic, while the cytoplasm near the periphery of the cell is pale and foamy in appearance.
Touton giant cells are formed by the fusion of macrophage-derived foam cells. It has been suggested that cytokines such as interferon gamma, interleukin-3, and M-CSF may be involved in the production of Touton giant cells.
Cytokines are a broad and loose category of small proteins important in cell signaling. Cytokines are peptides, and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine, paracrine and endocrine signaling as immunomodulating agents. Their definite distinction from hormones is still part of ongoing research.
Phagocytes are cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel". They are essential for fighting infections and for subsequent immunity. Phagocytes are important throughout the animal kingdom and are highly developed within vertebrates. One litre of human blood contains about six billion phagocytes. They were discovered in 1882 by Ilya Ilyich Mechnikov while he was studying starfish larvae. Mechnikov was awarded the 1908 Nobel Prize in Physiology or Medicine for his discovery. Phagocytes occur in many species; some amoebae behave like macrophage phagocytes, which suggests that phagocytes appeared early in the evolution of life.
A granuloma is a structure formed during inflammation that is found in many diseases. It is a collection of immune cells known as macrophages. Granulomas form when the immune system attempts to wall off substances it perceives as foreign but is unable to eliminate. Such substances include infectious organisms including bacteria and fungi, as well as other materials such as foreign objects, keratin and suture fragments.
Interleukins (ILs) are a group of cytokines that were first seen to be expressed by white blood cells (leukocytes). ILs can be divided into four major groups based on distinguishing structural features. However, their amino acid sequence similarity is rather weak. The human genome encodes more than 50 interleukins and related proteins.
An osteoclast is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and remodelling of bones of the vertebral skeleton. The osteoclast disassembles and digests the composite of hydrated protein and mineral at a molecular level by secreting acid and a collagenase, a process known as bone resorption. This process also helps regulate the level of blood calcium.
Interleukin 12 (IL-12) is an interleukin that is naturally produced by dendritic cells, macrophages, neutrophils, and human B-lymphoblastoid cells (NC-37) in response to antigenic stimulation. IL-12 belongs to the family of interleukin-12. IL-12 family is unique in comprising the only heterodimeric cytokines, which includes IL-12, IL-23, IL-27 and IL-35. Despite sharing many structural features and molecular partners, they mediate surprisingly diverse functional effects.
Interferon gamma (IFNγ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock as a product of human leukocytes stimulated with phytohemagglutinin, and by others as a product of antigen-stimulated lymphocytes. It was also shown to be produced in human lymphocytes. or tuberculin-sensitized mouse peritoneal lymphocytes challenged with PPD; the resulting supernatants were shown to inhibit growth of vesicular stomatitis virus. Those reports also contained the basic observation underlying the now widely employed interferon gamma release assay used to test for tuberculosis. In humans, the IFNγ protein is encoded by the IFNG gene.
A giant cell is a mass formed by the union of several distinct cells, often forming a granuloma. It can arise in response to an infection, such as from tuberculosis, herpes, or HIV, or foreign body. These multinucleate giant cells (MGCs) are cells of monocyte or macrophage lineage fused together.
A histiocytoma in the dog is a benign tumor. It is an abnormal growth in the skin of histiocytes (histiocytosis), a cell that is part of the immune system. A similar disease in humans, Hashimoto-Pritzker disease, is also a Langerhans cell histiocytosis. Dog breeds that may be more at risk for this tumor include Bulldogs, American Pit Bull Terriers, American Staffordshire Terriers, Scottish Terriers, Greyhounds, Boxers, and Boston Terriers. They also rarely occur in goats and cattle.
Foam cells are a type of cells that contain cholesterol. These can form a plaque that can lead to atherosclerosis and trigger heart attacks and stroke.
Interleukin-18 is a protein which in humans is encoded by the IL18 gene. The protein encoded by this gene is a proinflammatory cytokine. Many cell types, both hematopoietic cells and non-hematopoietic cells, have the potential to produce IL-18. It was first described in 1989 as a factor that induced interferon-γ (IFN-γ) production in mouse spleen cells. Originally, IL-18 production was recognized in Kupffer cells, liver-resident macrophages. However, IL-18 is constitutively expressed in non-hematopoietic cells, such as intestinal epithelial cells, keratinocytes, and endothelial cells. IL-18 can modulate both innate and adaptive immunity and its dysregulation can cause autoimmune or inflammatory diseases.
Interleukin-29 (IL-29) is a cytokine and it belongs to type III interferons group, also termed interferons λ (INF-λ). IL-29 plays an important role in the immune response against pathogenes and especially against viruses by mechanisms similar to type I interferons, but targeting primarily cells of epithelial origin and hepatocytes.
Chemokine ligand 9 (CXCL9) is a small cytokine belonging to the CXC chemokine family that is also known as monokine induced by gamma interferon (MIG). The CXCL9 is one of the chemokine which plays role to induce chemotaxis, promote differentiation and multiplication of leukocytes, and cause tissue extravasation.
The foreign body granuloma is a response of biological tissue to any foreign material in the tissue. Tissue-encapsulation of an implant is part of this. An inflammation around a splinter is part of this, too.
According to a common point of view Epithelioid cells are derivatives of activated macrophages resembling epithelial cells.
Multinucleate cells are eukaryotic cells that have more than one nucleus per cell, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coordinated, synchronous manner where all nuclei divide simultaneously or asynchronously where individual nuclei divide independently in time and space. Certain organisms may have a multinuclear stage of their life cycle. For example, slime molds have a vegetative, multinucleate life stage called a plasmodium.
Type IV hypersensitivity is often called delayed type hypersensitivity as the reaction takes several days to develop. Unlike the other types, it is not antibody-mediated but rather is a type of cell-mediated response. This response involves the interaction of T-cells, monocytes, and macrophages.
The pluripotency of biological compounds describes the ability of certain substances to produce several distinct biological responses. Pluripotent is also described as something that has no fixed developmental potential, as in being able to differentiate into different cell types in the case of pluripotent stem cells.
The Xanthogranulomatous Process (XP), is a form of acute and chronic inflammation characterized by an exuberant clustering of foamy macrophages among other inflammatory cells. Localization in the kidney and renal pelvis has been the most frequent and better known occurrence followed by that in the gallbladder but many others have been subsequently recorded. The pathological findings of the process and etiopathogenetic and clinical observations have been reviewed by Cozzutto and Carbone.
Histopathology of dermatitis can be performed in uncertain cases of inflammatory skin condition that remain uncertain after history and physical examination.
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