melanocytic nevus

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Related to melanocytic nevus: Ancient Melanocytic Nevus, Dysplastic nevus


 [ne´vus] (pl. ne´vi) (L.)
a circumscribed stable malformation of the skin or sometimes the oral mucosa, which is not due to external causes; the excess (or deficiency) of tissue may involve epidermal, connective tissue, adnexal, nervous, or vascular elements. Most are either brown, black, or pink; they may appear on any part of the skin, vary in size and thickness, and occur either in groups or alone. See also mole.

A nevus is usually not troublesome unless it is unsightly or disfiguring or becomes inflamed. If it changes noticeably, malignancy may be suspected, especially if any of the following are present: a highly irregular border, an uneven (pebbly) surface, or a mixture of colors (especially black, gray, or blue). Any change in size, color, or texture, or any bleeding or excessive itching, should be reported to a health care provider. Nevi can be removed by surgery or by other methods such as the application of solid carbon dioxide, injections, or radiotherapy.
nevus ara´neus vascular spider.
blue nevus a dark blue nodular lesion composed of closely grouped melanocytes and melanophages in the mid-dermis.
blue rubber bleb nevus a hereditary condition marked by multiple bluish cutaneous hemangiomas with soft raised centers, frequently associated with hemangiomas of the gastrointestinal tract.
nevus comedo´nicus a rare epidermal nevus marked by one or more patches 2 to 5 cm or more in diameter, in which there are collections of large comedones or comedolike lesions. This condition is occasionally associated with other lesions such as ichthyosis, vascular nevi, and cataracts.
compound nevus a nevocytic nevus composed of fully formed nests of nevus cells in the epidermis and newly forming ones in the dermis.
connective tissue nevus any nevus found in the dermal connective tissue with nodules, papules, plaques, or combinations of such lesions. Histologically, there is inconstant focal or diffuse thickening and abnormal staining of collagen.
epidermal nevus (epithelial nevus) a circumscribed congenital developmental anomaly resulting in faulty production of mature or nearly mature cutaneous structures; such nevi vary widely in appearance, size, and distribution and are commonly hyperkeratotic.
nevus flam´meus a congenital vascular malformation involving mature capillaries, present at birth. It consists of a reddish purple lesion that is flat or barely elevated and does not fade with age. It is a benign condition but may be associated with other syndromes such as sturge-weber syndrome. The dark variety is called a port-wine stain and a light variety is called a salmon patch. (See Atlas 1, Part E).
giant congenital pigmented nevus (giant hairy nevus) (giant pigmented nevus) any of a group of large, darkly pigmented hairy nevi, usually bilaterally symmetrical and present at birth; the most common locations are the chest, upper back, shoulders, arms, legs, and or hip and groin area. These nevi are associated with other cutaneous and subcutaneous lesions, as well as neurofibromatosis and other developmental anomalies, and they exhibit a predisposition to development of malignant melanoma.
halo nevus a pigmented nevus surrounded by a ring of depigmentation; called also leukoderma acquisitum centrifugum, Sutton's disease, and Sutton's nevus.
intradermal nevus a type of nevocytic nevus clinically indistinguishable from compound nevus, in which the nests of nevus cells lie exclusively within the dermis.
nevus of Ito a mongolian spot–like lesion having the same features as nevus of Ota except for localization to the areas of distribution of the posterior supraclavicular and lateral cutaneous brachial nerves, involving the shoulder, side of the neck, supraclavicular areas, and upper arm.
junction nevus (junctional nevus) a brownish, smooth, flat or slightly raised nevocytic nevus; histologically, there are nests of melanin-containing nevus cells at the dermoepidermal junction. (See Atlas 2, Part N.)
nevus lipomato´sus one that contains much fibrofatty tissue.
melanocytic nevus any nevus, usually pigmented, composed of melanocytes.
nevocytic nevus (nevus cell nevus) the most common type of nevus, usually more or less hyperpigmented, initially flat but soon becoming elevated, composed of nests of nevus cells. These nevi are classified as compound, intradermal, or junction according to the histologic pattern and location of nevus cells. Called also mole.
nevus of Ota (Ota's nevus) a persistent mongolian spot–like lesion, usually present at birth and unilateral, involving the conjunctiva and skin about the eye, as well as the sclera, ocular muscles, retrobulbar fat, periosteum, and buccal mucosa. It is a blue or gray-brown patchy area of pigmentation that grows slowly and becomes deeper in color. Although the lesion is benign, malignant melanoma occasionally develops, usually in the iris.
pigmented nevus (nevus pigmento´sus) one containing melanin; the term is usually restricted to nevocytic nevi (moles), but may be applied to other nevi that have pigmentation.
sebaceous nevus (nevus sebaceus of Jadassohn) an epidermal nevus of the scalp or less often the face, frequently growing larger during puberty or early adult life. In later life, some lesions may give rise to a variety of new growths, including basal cell carcinoma.
nevus sim´plex salmon patch.
spider nevus vascular spider.
nevus spi´lus a smooth, tan to brown, macular nevus composed of melanocytes and speckled with smaller, darker macules.
spindle and epithelioid cell nevus a benign compound nevus occurring most often in children before puberty, composed of spindle and epithelioid cells located mainly in the dermis, sometimes in association with large atypical cells and multinucleate cells, and having a close histopathological resemblance to malignant melanoma.
nevus spongio´sus al´bus muco´sae white sponge nevus.
Sutton's nevus halo nevus.
nevus uni´us la´teris a wartlike epidermal nevus, ranging from flesh colored to brown, found in a linear, unilaterally distributed pattern; on the extremities, the lesions usually follow the long axis, and on the trunk, they usually have a transverse orientation.
vascular nevus (nevus vascula´ris) (nevus vasculo´-sus) any of various reddish swellings or patches on the skin due to hypertrophy of capillaries; the term includes nevus flammeus, strawberry hemangioma, blue rubber bleb nevus, vascular spider, and cavernous hemangioma.
white sponge nevus a spongy white nevus of a mucous membrane, occurring as a hereditary condition.

melanocytic nevus

a congenital pigmented lesion of the skin caused by a disorder involving melanocytes.

melanocytic nevus

A benign mucocutaneous lesion that contains nevus cells and nevus cell nests.

Melanocytic nevi
Acquired nevus
A melanocytic nevus that is not congenital or not present at birth. (E.g., junctional nevus, compound nevus, intradermal nevus.)

Blue nevus
A mole that owes its deep blue colour to spindle-shaped melanocytes deep in the dermis, caused by the so-called Tyndall effect. The epidermis is normal.

Compound nevus
A nevus that is a mixture of junctional and intradermal melnocytic proliferation. It is slightly raised and brown to black, congenital or acquired, and includes so-called beauty marks.

Congenital nevus
A variably sized nevus that is present at or near time of birth. The bigger they are, the higher the risk that they may become melanomas.
Dysplastic nevus (Nevus of Clark)
A nevus with cellular and architectural dysplasia. Dysplastic nevi can be flat or raised, and are typically larger than normal nevi, with irregular borders and irregular pigmentation (thus resembling melanoma), which mandates excision. Dysplastic nevi are markers of increased risk of melanoma if numerous (atypical mole syndrome) and may develop into melanoma.

Giant pigmented nevus
A large, pigmented, congenital nevus, which is often covered by hair. 10–15% are associated with melanoma.

Intradermal nevus
A nevus in which the melanocytes are confined to the dermis. They are raised and often non-pigmented, and invariably benign.
Intramucosal nevus
A junctional nevus of the oral (usually on the hard palate) or genital mucosa.

Mongolian spot
Congenital large, deep, bluish discolouration on the back of Asian infants.

Nevus of Ito, Nevus of Ota
Either of two congenital, flat brownish nevi on the face or shoulder.

Recurrent nevus
Any incompletely removed nevus with residual melanocytes left in the surgical wound, thereby creating a dilemma for the patient and physician as the histology may be suggestive of a melanoma.

Spitz nevus
A distinct variant of intradermal nevus that usually occurs in children; they are raised and reddish (non-pigmented). A pigmented variant, called the nevus of Reed, typically appears on the leg of young women.

melanocytic nevus

The most common nevus, characterized by melanocytes in the dermis or epidermis
Melanocytic nevi
Compound nevus Nevus cells and nests at the dermal-epidermal interface–the 'junction' and dermis
Intradermal nevus Nevus cells and nests confined to dermis
Junctional nevus Nevus cells and nests confined to dermal-epidermal interface
Spindle & epithelioid cell nevus of Spitz A compound nevus with elongated and/or epithelioid nevus cells and nests present at the dermal-epidermal interface–the 'junction' and in the dermis; it is histologically bizarre but benign  


pl. nevi [L.] a circumscribed stable malformation of the skin and occasionally of the oral mucosa, which is not due to external causes; the excess (or deficiency) of tissue may involve epidermal, connective tissue, adnexal, nervous, or vascular elements; called also mole.

blue nevus
a dark blue nodular lesion composed of closely grouped melanocytes and melanophages situated in the mid-dermis.
connective tissue nevus
any nevus occurring in the dermal connective tissue and characterized by nodules, papules or plaques, or by combinations of such lesions. Histologically, there is inconstant focal or diffuse thickening and abnormal staining of collagen.
epidermal nevus
congenital skin tumors that do not contain melanocytes, which vary widely in appearance, size and distribution, and which are commonly hyperkeratotic.
hair follicle nevus
occur on the proximal extremities and have thick, brushlike hairs protruding.
intradermal nevus
a nevocytic nevus in which the nevus cells occur in nests in the upper part of the dermis, with no evidence of the proliferative process by which they originated.
melanocytic nevus
any nevus, usually pigmented, composed of melanocytes. See also melanoma.
pigmented nevus, nevus pigmentosus
one containing melanin; the term is usually restricted to nevocytic nevi (moles), but may be applied to other pigmented nevi.
sebaceous nevus
an epidermal nevus containing an overgrowth of sebaceous glands, frequently growing larger during puberty or early adult life, and rarely giving rise to a variety of new growths, including basal cell carcinoma.
nevus vascularis, nevus vasculosus, vascular nevus
a reddish swelling or patch on the skin due to hypertrophy of the skin capillaries. Seen on the scrotum of old dogs, sometimes bleeding.
References in periodicals archive ?
D, Dysplastic junctional melanocytic nevus showing architectural atypia with bridging of irregular junctional nests (hematoxylin-eosin, original magnifications X20 [A, B, and D] and X100 [C]).
2) Removal of a medium size melanocytic nevus whether congenital or acquired over exposed parts, especially over face is warranted for its cosmetic, embarrassment rather than for its potential to cause malignancy.
dermal cells support a diagnosis of a neurotized melanocytic nevus rather than a neurofibroma.
Chang Y, Newton-Bishop JA, Bishop DT, Armstrong BK, Bataille V, Bergman W, Berwick M, Bracci PM, Elwood JM, Ernstoff MS, Green AC, Gruis NA, Holly EA, Ingvar C, Kanetsky PA, Karagas MR, Le Marchand L, Mackie RM, Olsson H, Osterlind A, Rebbeck TR, Reich K, Sasieni P, Siskind V, Swerdlow AJ, Titus-Ernstoff L, Zens MS, Ziegler A, Barrett JH: A pooled analysis of melanocytic nevus phenotype and risk of cutaneous melanoma at different lattitudes.
Most melanomas arising on chronically sun-damaged skin have a characteristic histologic appearance, whereas those arising on intermittently sun-exposed skin or within a preexisting melanocytic nevus have more variable features.
Big patch involving trunk, buttocks and thighs and many small lesions elsewhere in the body closely mimicked giant congenital melanocytic nevus.
Pseudomelanoma: recurrent melanocytic nevus following partial surgical removal.
58) Although the discriminating power of BRAF mutation status is limited in the distinction of a melanoma from a melanocytic nevus, it may identify a distinct melanoma histologic subtype with a predictable clinical outcome.
Some of these disorders may have prognostic implications like congenital melanocytic nevus (CMN),1,2 and some, such as epidermolysis bullosa,3 mandate genetic counseling and family planning.
To reflect the often worrying histologic features, which can suggest a possible diagnosis of melanoma, the term atypical melanocytic nevus of genital type was subsequently proposed by Clark et al (8) in 1998.
Deep penetrating nevus (DPN) is a distinctive melanocytic nevus originally described by Seab et al (1) in 1989.
There is some controversy about the risk for progression of congenital melanocytic nevus (CMN) to melanoma.