Dermatological terminology

Introduction

This glossary describes dermatopathological terms. It is arranged alphabetically. If you can't find what you're looking for on this list, try our general glossary, the A - Z Topic index, or the DermNet search box.

Acantolysis

Acantolysis is the separation of keratinocytes within epidermis due to loss of accession between keratinocytes. Acantholysis occurs due to failure of the integrity of the intercellular /intraepidermal Cell junctions. This leads to separation of the epithelial cells with swelling of the epithelial cells ("balloon degeneration"). In pemphigus foliaceus, there is keratinocyte acantholysis just below the granular layer of the epidermis. In comparison, in pemphigus vulgaris there is separation in the basal cap leading to a "gravestone pattern" of keratinocytes where there is retention of some but not all keratinocytes in the basement membrane.

Acantolytic dyskeratosis

Acantolytic dyskeratosis is the reaction pattern characterized by suprabasal cleft and acantholysis and dyskeratotic Keratinocytes Acantolytic dyskeratosis can be seen in a variety of conditions, but generally Darier's disease, Hailey-Hailey disease, and Grover's disease. The characteristic dyskeratotic cells of acantholytic dyskeratosis are body rounds and body grains. The bodies of the bodies are round dyskeratotic cells with dense basophilic (blue) cytoplasm (usually acidophilic, pink) with a light area around the core (or peri-nuclear halo), which is usually located near the basal layer. The grains of the body are small cells, with elongated nuclei and it is found in the upper layers of the epidermis.

Acanthosis

Acanthosis is a thickening of the epidermis and elongation of the challenge ridges due to thickening of the spiny layer +/- enlargement of rete pegs. Typical examples include chronic eczematous reactions

Anagen

Anagen is the growth phase of the hair follicle.

Apoptosis

Apoptosis is the normal regulated physiological The process by which a cell undergoes a process of death / self-destruction in the presence of a suitable signal from the cell's command center, the nucleus. In the epidermis apoptotic keratinocytes are usually solitary, scarce and located in the basal layer. They typically have a dark, condensed core chromatin (pyknosis), chromatin marginalization below the nuclear membrane, followed by nucleus fragmentation (karyorrhexis). Apoptotic cells are smaller than healthy keratinocytes, usually single cells in the basal cells in the epidermal layer, sometimes some scattered in the upper layers of the epidermis.

• Apoptosis of the keratinocytes of the basal layer results in "bodies of Civatte" (in lichen planus and other lichenoid type reactions) or "sunburn cells" (in acute Sun tanning).
• Civatte body is synonymous with "cytoid body", "colloidal body" or "curb bodies "and refers to a eosinophilic remnant of a keratinocytes within the basal or upper papillary layer dermis. 'Hyaline the bodies are equivalent but occur in connective tissue.
• In some drug reactions, apoptotic keratinocytes can be seen in the basal layer or dispersed in the lower layers of the epidermis.
• In graft versus host disease, apoptotic keratinocytes are seen in association with one or two adjacent lymphocytes in the basal layer and are called 'satellite cell necrosis'.

Atrophy

Atrophy refers to a reduction in the size of an organ or part of an organ. In the skin, it can be a reduction in the thickness of the various layers of the skin, for example, epidermal atrophy, dermal atrophy, atrophy of panniculus.

• Epidermal atrophy is characterized by reduction in the number of epidermal cells leading to reduced thickness of the epidermis. Epidermal atrophy can occur after inflammation dermal skin (for example lichen sclerosus) or may occur after some skin treatments (for example after long-term use of current corticosteroids).
• Dermal atrophy is due to thinning of the dermal layer due to loss of collagen me elastin. It can occur in aplasia skin, atophroderma, or after severe inflammatory skin reactions affecting the superficial dermis.
• Panniculus atrophy is called lipoatrophy. Lipoatrophy can be congenital or acquired: after skin inflammation (for example, deep morpho, deep lupus), drug treatments (for example, some antiHIV drugs), or trauma.

Basement membrane

The basement membrane is thin, nocellular layer between the epidermis and the dermis and is made up of several protein structures that link the basal layer of keratinocytes to the basement membrane (hemidesmosomes), and the basement membrane to the underlying dermis (anchorage fibrils) The basement membrane plays an important role in ensuring that the epidermis adheres to the underlying dermis. In electron microscopy, the basement membrane consists of 3 layers:

1. The lamina lucida
2. The dense lamina
3. The reticular lamina.

Birefringence

Birefringence is the physical property of substances to refract light differently depending on the direction of the light and the state of polarization of the light. Amyloid the deposits show "apple green" birefringence under polarized light.

Bulla(me)

Bulla (e) large fluid-filled bullae arising from separation within the epidermis (intraepidermal bulla) or below the basement membrane (subepidermal bulla). Small blisters are called vesicles.

Calcinosis skin

Calcinosis cutis refers to the statement calcium in the skin.

Catagen

Catagen is the involutional phase of the hair cycle. There is apoptosis of the cells in the lower part of the hair follicle.

Cornoids sheet

The cornoid lamina is a high intraepidermal layer of parakeratotic skin scale covering a focal area of hypogranulosis and dyskeratotic keratinocytes. Cornoid laminae are the characteristic feature of porokeratosis and some rare forms of epidermis. naevi.

Cortex

The cortex is the dry concretion of parakeratotic keratinocytes, serum and inflammatory cells within the stratum corneum.

Cyst

A cyst is a closed, thin-walled capsule or sac-like structure, filled with fluid, solid or semi-solid material. Cysts have an epithelial lining. A pseudocyst It's similar injury but it lacks an epithelial lining.

Dermal edema

Dermal edema is the process by which fluid leaks out of the blood and lymphatic channels in the surrounding dermis leading to the separation of collagen bundles.

Dermis

The dermis is the fibrous layer of the skin immediately below the epidermis. This layer contains predominantly collagen but also elastin fibers that contribute to the flexibility of the skin. It also contains blood vessels, nerves, attached structures like hair follicles, eccrine (sweat glands, sebaceous glands and other structures. The dermis has 2 distinct regions:

1. the tallest papillary dermis containing fine collagen fibrils
2. the thickest and deepest layer that forms thick bundles of collagen.

Dyskeratosis

Dyskeratosis is the presence of premature or altered / abnormal keratinocytes. differentiation. Histologically abnormal keratinocytes have an increase / accumulation of keratin filaments leading to hypereosinophilic cytoplasm (more pink in H&E) and shrunken hyperchromatic nuclei (that is, they are small and dark).

Elastosis

Elastosis is a histological process of increasing the number of elastic fibers on the skin Elastic fibers are responsible for the flexibility of the skin, contributing to the skill of fingers

Flame figures

Flame figures are pink degenerate collagen bundles (eosinophils) and eosinophils granules. Flame figures can be seen in Wells syndrome (eosinophilic cellulite).

Foam cells

The foam cells are lipid (or fat) loaded histiocytes/ / macrophages.

Epidermis

The epidermis is the top layer of the skin. It consists of 4 layers, from the deepest to the most superficial:

1. Basal layer (basal layer)
2. Spinous stratum (thorny layer)
3. Granular layer (granular layer)
4. Stratum corneum (horny layer)

The stratum basalis contains the regenerative cells of the epidermis and is sometimes called the "Malpighian layer."

Epidermolytic dyskeratosis

Epidermolytic dyskeratosis is an abnormal epidermal maturation characterized by vacuolate degeneration of the stratum granulosa and stratum spinulous with compact hyperkeratosis of the stratum corneum. Epidermolytic dyskeratosis can be seen in some forms of palmoplantar keratoderma, bullous ichthyosis, in association with linear or systematized epidermal nevi, epidermolytic acanthomas or focally in some epidermal lesions.

Epidermotropism

Epidermotropism is the abnormal migration of atypical lymphocytes in the epidermis of the skin. It is the hallmark of the initial stage cutaneous T cell lymphoma (mycosis fungoides). The term is sometimes used to refer to the invasion of evil one cells in the epidermis.

Exocytosis

Exocytosis is the random migration of inflammatory cells, such as lymphocytes, neutrophils, basophils, in the epidermis. It is induced by cytokine release in inflammatory processes of the epidermis.

Fibrinoid necrosis

Fibrinoid necrosis refers to extravasation of fibrin on the walls of the vessels and the surrounding dermis interstice in association with leukocytoclastic vasculitis.

Fibrosis

Fibrosis is the process by which the body deposits collagen as part of the healing process. Fibrosis may be a consequence of the normal healing response leading to a scar, or it may occur in abnormal amounts (eg, scar formation) and / or in abnormal patterns (eg, keloid scar formation). A slight increase in vertical / parallel papillary dermal collagen deposition ridge crests ('stripes') may be seen in chronic inflammatory conditions (eg, lichen simplex chronicus, chronic eczematous reactions).

Follicular plug

Follicular plugging is an abnormal accumulation of keratin in the shoulder region of the hair follicle in response to an inflammatory reaction. It can be seen in the lichenoid reaction pattern, especially lichen planopilaris, pityriasis rubra pilaris and cutaneous lupus erythematosus.

Granuloma

A granuloma is a chronic inflammatory pattern characterized by located aggregation histiocytes with or without other inflammatory cells (eg. plasma cells, eosinophils, neutrophils), with or without necrosis, with or without vasculitis, with or without calcification, with or without foreign bodies. It may be due to infection or chronic inflammatory disease or reactions to foreign material.

Grenz area

Grenz's zone is an apparent area of unaffected papillary dermis that separates the epidermis from inflammation or tumor cell infiltrate of the dermis.

Hemophagocytosis

Hemophagocytosis is the presence of histiocytes / macrophages that phagocytosis red blood cells, leukocytes, red blood cells or platelets in the bone marrow or other tissues. The phagocytic cells are called 'bean bag cells'. Hemophagocytosis can occur in hemophagocytic lymphohistiocytosis in various infections (EBV), malignancy, genetic and autoimmune syndromes

Hemosmosin statement

Hemosiderin deposition is the process by which iron released from degradation extravasated Red blood cells settle in the dermis on the skin, leaving dark brown or rusty orange marks. Commonly seen in the lower legs after any inflammatory process, for example capillaritis venous stasis eczema.

horn cyst

The horn cyst is a keratin-filled space within an island of the epithelium. Commonly seen in seborrheic keratosis and something melanocytic naevi.

Hypergranulosis

Hypergranulosis is an increase in the intracellular keratinocyte granules within the granular layer. Commonly seen in viral warts.

Hyperkeratosis

Hyperkeratosis is the thickening of the epidermis due to the thickening of the stratum corneum with normal epidermal differentiation. In normal skin, there is a loose “basket weave” appearance. In hyperkeratosis, there is usually thickening and lamination or compaction of the stratum corneum.

Hyalinization collagen

Hyalinization (or homogenization) of collagen refers to the degeneration of the collagen of the superficial dermis into a smooth granular layer. Commonly seen in lichen sclerosus.

Inflammation

Inflammation is the complex multi-step coordinated process by which the body tries to eliminate or contain foreign material /organisms of the body and / or repair any injury suffered by the tissues. The inflammatory process can be acute or chronic in nature, reflecting the time frame during which this takes place.

Interface dermatitis

Dermatitis interface generally refers to a mild lichenoid-like reaction at the interface between the epidermis and the dermis. There are scattered scattered lymphocytic infiltration centered around the basal layer +/- vacuolar degeneration of the basal layer. Unlike a classic lichenoid reaction, the inflammatory infiltrate does not obscure the basement membrane.

Keratinization

Keratinization is the process by which epidermal cells (keratinocytes) undergo maturation and differentiation as the cell migrates from the basal layer to the stratum corneum. There is gradual loss of nuclear function (with eventual loss of nuclei in the stratum corneum), loss of cytoplasmic structures, and progressive formation of keratin filaments to form the cornified envelope.

Koilocytes

Koilocytes are epidermal cells infected by the wart virus. Cells appear pale with vacuolated cytoplasm and have a small dark condensed nucleus (pyknotic). The cells have prominent keratohyalin granules in the cytoplasm (hypergranulosis).

Leukocytoclasia

Leukocytoclasia is the breakdown of neutrophils nuclei in fragments or nuclear dust. Often seen in inflammatory disorders with intense neutrophil-rich inflammatory infiltrate, such as vasculitis, Sweet's syndrome.

Lichenoid reaction

The lichenoid reaction is a dense lymphocytic inflammatory infiltrate centered in the basal layer of the epidermis and upper dermis. The basement membrane is darkened, and there is often vacuolar degeneration or bodies of Civatte in the basal layer of the epidermis. Lichenoid inflammation pattern is seen in lichen planus, drug reactions, cutaneous lupus erythematosus, lichen nitidus, erythema multiform

Mucinosis

Mucinosis or myxomatous Instead, it is the deposition of fine, granular, fibrous basophilic material in structures or layers within the skin, within the dermis (eg, dermal mucinosis), epidermis (eg, small foci seen associated with scaly cell carcinomas, basal cell carcinomas) or within skin structures such as hair follicles (eg, follicular mucinosis). Mucinosis can occur in association with inflammatory skin disorders, for example lupus erythematosus, lattice erythematous mucinosis Dermal deposition of mucin the dermis is usually acidic mucopolysaccharide (glycosaminoglycan), eg. ex. pretibial myxedema, papular mucinosis, scleromyxedema.

Necrobiosis

Necrobiosis is an accumulation of acidic mucopolysaccharides around the collagen bundles that give the collagen bundles a bluish (basophilic), indistinct, or fuzzy appearance. Necrobiosis can be seen in granuloma annulare and lipoid necrobiosis.

Necrosis

Necrosis is the death of a cell or tissue induced by toxins, trauma, infection or factors external to the cell or tissue. Types of necrosis include:

1. coagulative necrosis (normal tissue becomes gel-like tissue structure but retaining, generally due to ischemia)
2. liquefaction necrosis (tissue becomes liquid due to digestion of tissue with loss of structure, usually seen with purulent infections)
3. gangrenous necrosis (a type of coagulative necrosis that leads to mummification of tissue, may be complicated by liquefactive necrosis)
4. caseous necrosis (a mixture of coagulative and liquefactive necrosis that leads to friable cheese-like mycobacterial infection)
5. fat necrosis (a specific type of lipase-induced necrosis, eg. pancreatitis)
6. fibrinoid necrosis (necrosis induced by vascular damage from immune complex formation, for example vasculitis).

Neoplasm

The neoplasm is a proliferation and accumulation of an abnormal cell due to mutation(s) or factors that promote cell growth and / or loss of inhibition of cell death and / or loss of the ability of immune function, which allows the identification and destruction of abnormal cells. The cells of a neoplasm are generally derived from the same cell line (a clone proliferation) but may come from normal, unaffected skin. Neoplasms maybe benign (that is, they do not have the potential to spread to distant sites through the blood or lymphatic system) or malignant (that is, they have the potential to spread to distant sites in the body, also called metastasis. Neoplasms can grow locally with no propensity to spread to the blood or lymphatic systems.

Nodular infiltrate

Nodular infiltrate is a nonspecific term that describes inflammation within the skin in a discreet ("Nodular") on the skin.

Edema

Edema is an accumulation of plasma in the tissues that leads to the scavenging of the affected layer. Edema can occur in the dermal interstitium (dermal edema), due to reduced hydrostatic pressure in the blood vessels, reduced albumin or secondary to inflammation, or within the epidermal layer (spongiosis)

Osteoma skin

Osteoma cutis is ectopic development of bone in the skin, most commonly after acne.

Orthokeratosis

Orthokeratosis is the normal "basket-weave" appearance of the stratum corneum seen in normal skin. In acral skin (palms or soles), the stratum corneum exhibits thickening and compaction ('orthokeratosis compacta').

Pagetoid spread

Pagetoid spread refers to the proliferation of cells within the epidermis in a random pattern of distribution giving a scattered appearance of "buckshot". This appearance can be seen in malignant melanoma, enfermedad de Paget extramamaria y ocasionalmente en células escamosas carcinoma in the place.

Panniculus

El panículo es la capa más profunda de la piel y está compuesto predominantemente por células grasas.

Panniculitis

La paniculitis es un proceso inflamatorio centrado alrededor de la grasa. La paniculitis puede deberse a traumatismo, vasculitis o primary inflammatory infiltrators centrado alrededor de las estructuras del panículo (subcutaneous grasa).

• La inflamación centrada alrededor de las colecciones (o lobulillos) de las células grasas se llama paniculitis lobular.
• Inflamación centrada alrededor de los tabiques fibrosos del panículo (las áreas de circulación a través de las células grasas que contienen arterioles, venulesnerves lymphatic, células fibrohistiocíticas), se llama paniculitis septal.
• La paniculitis a menudo exhibe un patrón mixto con componentes lobulares y septales. La paniculitis puede verse en asociación con vasculitis y / o granulomas.

Papillary mesenchymal bodies

Los cuerpos mesenquimales papilares son el rasgo característico del tricoepitelioma, donde hay agregación focal de fibroblasts debajo del epitelio que intenta formar folículos pilosos.

Papillomatosis

La papilomatosis es la hyperkeratotic y aspecto ondulante de la epidermis sobre la piel normal circundante. La papilomatosis se asocia con hyperproliferation de queratinocitos. La papilomatosis se puede ver en verrugas virales, queratosis seborreicas, confluent y papilomatosis reticulada.

Parakeratosis

La paraqueratosis es la retención anormal de los núcleos de queratinocitos dentro del estrato córneo. La presencia de paraqueratosis indica que la epidermis se ha inflamado o lesionado.

Pautrier microabscess

El microabsceso de Pautrier es una colección intraepidérmica de linfocitos dentro del estrato basal y el estrato espinoso en el linfoma cutáneo de células T (micosis fungoide).

Perianexal inflammation

La inflamación perianexial es la presencia de lymphohistiocytic inflamación alrededor de estructuras pilosebáceas y anexas, por ejemplo, folículos pilosos, glándulas sebáceas, eccrine glands.

Perivascular infiltrado linfocítico

El infiltrado linfocítico perivascular se refiere a la inflamación centrada alrededor de los pequeños vasos en la piel. Suele ser un infiltrado inflamatorio linfocítico o linfohistiocítico, sin evidencia de daño vascular / muerte (vasculitis).

Pigment incontinence

La incontinencia pigmentaria es la deposición de melanin en la dermis superior debido a la inflamación que afecta la melanocytes dentro de la capa basal. La incontinencia pigmentaria se observa con mayor frecuencia después de, o en asociación con, reacciones liquenoides establecidas.

Pseudoepiteliomatoso hyperplasia

La hiperplasia pseudoepiteliomatosa se pronuncia engrosamiento debido a la proliferación de todas las capas de la epidermis con alargamiento irregular de las clavijas rete. Se puede observar hiperplasia pseudoepiteliomatosa en lesiones inflamadas crónicas. Puede imitar un pozodifferentiated squamous cell carcinoma.

Psoriasiform hyperplasia

La hiperplasia psoriasiforme es una hiperplasia epidérmica con alargamiento de las clavijas ret en un patrón regular y uniforme. Las apariencias se ven clásicamente en la psoriasis y otras afecciones inflamatorias psoriasifom.

Pustule

Una pústula es una colección de neutrófilos en la epidermis o dentro de un folículo piloso.

• Microabscesos son pequeños pustules.
• Microabscesos intraepidérmicos se observan en varios inflamatorios skin disease.
• Munro micro-abscess es una colección de neutrófilos, fibrina y restos celulares en el estrato córneo paraqueratótico en la psoriasis aguda o subaguda.
• the spongy Las pústulas de Kogoj son pequeñas colecciones de neutrófilos con espongiosis circundante en la capa espinosa en la psoriasis aguda o subaguda.
• Los microabscesos papilares son una colección de neutrófilos, con o sin eosinófilos en las puntas de la dermis papilar, en condiciones como dermatitis herpetiforme, scar pemphigoid
• Subcorneal las pústulas son colecciones de neutrófilos debajo del estrato córneo, por ejemplo, subcorneal pustular skin diseaseimpétigo agudo generalized exanthematous pustulosis.

Pyknosis

La picnosis es la aparición histológica de los cambios de la energía nuclear. chromosomal material (cromatina) del núcleo, ya que sufre apoptosis. Se caracteriza por la compactación y el oscurecimiento de la cromatina (picnosis) seguido de la fragmentación del núcleo (cariorrexis) y luego la desaparición del núcleo (cariólisis).

Scale bark

La corteza escamosa es áreas localizadas del estrato córneo, donde hay paraqueratosis, células inflamatorias y suero que surgen de una enfermedad inflamatoria de la piel, por ejemplo, afecciones cutáneas eccematosas infectadas.

Solar elastosis

La elastosis solar es degenerative Cambio basófilo de las fibras de elastina y colágeno de la dermis en la piel dañada crónicamente por el sol.

Spongiosis

La espongiosis es el ensanchamiento de los espacios intercelulares entre los queratinocitos debido al edema intercelular que ocurre cuando la epidermis está inflamada. La espongiosis se observa clásicamente en asociación con infiltrados eosinófilos en la piel (espongiosis eosinofílica), pero también se puede ver en asociación con neutrófilos (neutrophilic spongiosis).

• La espongiosis eosinofílica es el patrón inflamatorio visto en atopic eccema, penfigoide ampolloso, fase aguda de incontinentia pigmenti.
• La espongiosis neutrofílica se puede observar en infecciones fúngicas, psoriasis (pústulas espongióticas de Kogoj), pustulosis exantematosa aguda generalizada.
• La espongiosis folicular se puede ver en la epidermis de la infundibulum de folículos pilosos en dermatitis atópica, miliaria, foliculitis eosinofílica

Scaly swirl

El remolino escamoso es la disposición de los queratinocitos concéntricos que rodean un área central de queratinización y surge en los carcinomas de células escamosas.

Telogen

Telogen es la fase de reposo del folículo piloso y dura meses. El telógeno ocurre después del catágeno y precede al anágeno.

Transepidérmico elimination

La eliminación transepitelial (o transepitelial) es el patrón de reacción histológica en el que se expulsa colágeno o elastina (y rara vez otras sustancias) desde la dermis a través de la epidermis. Los ejemplos incluyen colagenosis perforante adquirida, la elastosis realiza serpiginosa.

Tumor

El tumor es una proliferación anormal de células y normalmente implica la presencia de una neoplasia benigna o maligna. Los médicos también utilizan este término para describir un macroscopic hinchazón o un bulto en la piel.

Vacuolar Degeneration

La degeneración vacuolar (también llamada degeneración por licuefacción) es la intracelular. vacuole formación en queratinocitos basales lesionados y separación de la membrana celular plasmática de la membrana basal subyacente. La degeneración vacuolar se observa en reacciones liquenoides como lupus eritematoso cutáneo, dermatomiositis, reacción a medicamentos. Si la lesión es grave, la célula sufre apoptosis y se convierte en un cuerpo Civatte (cuerpo coloide).

Vasculitis

La vasculitis es un proceso inflamatorio caracterizado por daño (endothelial hinchazón) y / o muerte de las células del revestimiento endotelial de los vasos sanguíneos debido a la infiltración de células inflamatorias (generalmente neutrófilos). La vasculitis leucocitoclástica se refiere al daño endotelial por neutrófilos, con la desintegración de los núcleos de neutrófilos (leucocitoclasia) en fragmentos o polvo nuclear. Si las células son linfocitos, se conoce como “vasculitis linfocítica”, sin embargo, generalmente no hay leucocitoclasia presente. Algunas formas de vasculitis están asociadas con granulomatous inflamación (“vasculitis granulomatosa”).

Vesicle

Una vesícula es una pequeña ampolla llena de líquido dentro o debajo de la epidermis.

Viral inclusion bodies

Los cuerpos de inclusión viral son pequeñas estructuras anormales dentro del núcleo o citoplasma o ambos y se deben a una infección viral de una célula. Viral inclusions en la piel epidérmica las células tienen diferentes morphologies dependiendo del virus y se puede ver en el virus del papiloma humano (verruga), el virus del herpes, las infecciones por molusco contagioso.