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 ?
This can be difficult to distinguish from the bridging between adjacent rete ridges that is associated with dysplastic nevi, but the confluent growth of a melanoma often extends over the tops of the dermal papillae, rather than solely connecting the bases of adjacent rete ridges.
Knowing these risk factors, patients with a history of dysplastic nevi "need to have more frequent total body skin exams.
The immune response in halo nevi. J Am Acad Dermatol 1997;37:620-4.
If ischemia is truly present, then diminished blood flow in the superficial retina may explain the atrophic changes that are typically seen in the retina overlying some nevi [19].
* Neurocutaneous melanosis, a complication of giant congenital nevi, is a melanocyte proliferation in the central nervous system (CNS).
Fortunately, only 20 to 40 percent of melanomas develop from a pre-existing nevi, so moles are a marker of risk, and not necessarily a precursor to melanoma.
In the first study, the researchers observed that women with 15 or more nevi were 35 percent more likely to be diagnosed with breast cancer than women who reported no nevi, corresponding to an absolute risk of developing breast cancer of 8.48 percent in women with no nevi and 11.4 percent for women with 15 or more nevi.
Furthermore, Rad6 expression in the skin has not been investigated, and there are no data on the role of Rad6 in the pathogenesis of benign (nevi) and malignant (melanoma) melanocytic lesions.
Results: Pigmented birthmarks observed included Mongolian blue spot, cafe-au-lait macules and congenital melanocytic nevi. Among the ethnic groups these nevi were more prevalent among groups with darker skin colour and black hair.
Hu-Friedy announces the details of the "Host Nevi Scholarship Program" part of the "Host Nevi" campaign, which has a goal of raising $50,000 to support continuing education for practicing clinicians.