Nevus


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naevus

(US), nevus
any congenital growth or pigmented blemish on the skin; birthmark or mole

Nevus

 

(mole, birthmark), a congenital malformation of the skin in which some areas differ in color from the rest of the skin and/or have a peculiar warty appearance. Nevi are not confined to any particular area. They can be present at birth or develop during the first few years of life or even later.

Vascular nevi, or hemangiomas, are characterized by varying sizes, uneven edges, and a pink or bluish red color. They become pale when pressed and may be flat, superficial (capillary nevi), or nodular. They are embedded in the thickest part of the skin and have an uneven cavernous surface (cavernous nevi). Verrucoid nevi occur as singular or multiple patches of different shapes, are muddy gray or brown in color, and have an uneven keratotic surface. Pigmented nevi are light brown to almost black in color; they can be the size of a pinhead, or they can cover large areas of the skin. The surfaces of pigmented nevi may be uneven and covered with hair (Becker’s nevi).

Self-treatment of pigmented spots is dangerous because frequent injury may cause them to degenerate into melanomas, whereupon the nevi enlarge, become firmer, and change color. New pigmented spots may appear in the same area, and the regional lymph nodes may become enlarged.

Electrocoagulation, cryotherapy, surgical dissection, and radiotherapy are used to treat nevi.

REFERENCE

Shanin, A. P. “Nevusy.” In Mnogotomnoe rukovodstvo po dermatologii, vol. 3. Moscow, 1964.

I. IA. SHAKHTMEISTER

nevus

[′nē·vəs]
(medicine)
A lesion containing melanocytes.
References in periodicals archive ?
In a nevus, junctional melanocytes are arranged in a predominantly nested pattern, with the nests being of even size and regular distribution.
Of the RAS family, the HRAS pathway has been most closely associated with nevus sebaceous.
Becker's nevus (Melanosis) is an acquired melanosis that presents in late childhood or early adolescence.
An EAC nevus may cause conductive hearing loss because of its enlarging mass, causing obstruction of the EAC or possibly a keratosis obturans and cholesteatoma.
The diagnosis of a well-developed Becker's nevus is straightforward.
The association between nuchal nevus flammeus and alopecia areata: a case-control study.
The anatomopathological study was performed on 8 lesions and 4 pigmented basal cell carcinomas (lesions 1,18, 25, and 35), 1 junctional melanocytic nevus (lesion 21), and 3 melanomas (lesions 29, 32, and 40) were found.
Blue rubber bleb nevus syndrome is a rare congenital disorder with hallmarks of venous malformations on the skin and viscera.
Blue nevus is a rare lesion of dermal melanocytes most commonly found in the skin, but it has been reported in the oral mucosa, sclera, cervix, vagina, and prostate [27].
NS is a type of organoid nevus. Classically, it presents at infancy as a single bald patch over the scalp and generally remains unchanged until puberty after which the patch becomes more thickened and protuberant and at times verrucous or nodular, with a smooth velvety surface.[1] Among 202 cases of Chi et al .,[2] the most common site of NS was the scalp (66.8%), followed by the face (26.7%) and the neck (5.5%).
Excisional biopsy of the lesion showed islands of mature adipocytes in the papillary dermis, confirming the clinical diagnosis of nevus lipomatosus superficialis (Figure 2).