Nevus, also known as a mole, is the medical term for sharply circumscribed and chronic lesions of the skin or mucosa. These lesions are commonly named birthmarks or beauty marks. Nevi are benign by definition. However, 25% of malignant melanomas (a skin cancer) arise from pre-existing nevi. Using the term nevus and nevi loosely, most physicians and dermatologists are actually referring to a variant of nevus called the " melanocytic nevus", which are composed of melanocytes. Histologically, melanocytic nevi are distinguished from lentigines (also a type of benign pigmented macule) by the presence of nests of melanocytes, which lentigines (plural form of lentigo) lack.
The Collaborative International Dictionary
Naevus \N[ae]"vus\ (n[=e]"v[u^]s), n.; pl. N[ae]vi (-v[=i]). [L.] (Med.) A spot or mark on the skin of children when born; a birthmark; -- the term includes moles as wells a other types of birthmark, and is most commonly applied to reddish or brownish raised vascular areas of the skin, i. e., those consisting mainly of blood vessels, as dilated arteries, veins, or capillaries. [Usually spelled nevus.]
alt. (context anatomy English) A general term referring to a number of different, usually benign, pigmented, raised or otherwise abnormal lesions of the skin. n. (context anatomy English) A general term referring to a number of different, usually benign, pigmented, raised or otherwise abnormal lesions of the skin.
Usage examples of "nevus".
It was a nevus, a birthmark, a magenta discoloration just to the right of and a little above the brain stem.
I withdrew my hand, the image of the nevus clearly before me even though the old man had turned.
Until the time of pregnancy this mamma was taken for an ordinary nevus, but with pregnancy it began to develop and acquired the size of a citron.
When a babe the patient had, on the dorsum of the little finger, a small nevus, which was quiescent for many years.
He received a deep cut at the base of the thumb, and immediately after this accident the nevus began to enlarge rapidly.