nevus

n. congenital deviation of the skin, pigmented patch of skin, birthmark, mole (Medicine)

Nevus (or naevus) is a general term that refers to a number of different (usually benign) pigmented lesions of the skin. Most birthmarks and moles are placed into the category of nevi.Melanocytic nevus: Nevus cells are normally localized in the basal layer of the epidermis. Their proliferation may appear in the form of a:Junctional nevus: located just superficial to the junction of the epithelium and the underlying connective tissue. A junctional nevus is flat and is not detected by palpation.Compound nevus: located within the interface of the epithelium and the underlying connective tissue. A compound nevus is raised and solid.Intradermal nevus: The most common lesion of the skin, these lie exclusively within the dermis. They are regular and round, their cells having a central nucleus and single nucleolus. Some melanocytes may present melanin pigment in the cytoplasm (dark-brown, granular).Intramucosal nevus: Although all oral nevi are rare, intramucosal nevi are the most commonly seen there, as they are found most frequently on the hard palate.Spider angioma, also known as nevus araneusDysplastic nevusBlue nevusBlue Rubber Bleb Nevus SyndromeNevus flammeus (port-wine stain)Giant Hairy Nevus: These large pigmented (often hairy) congenital nevi are important because of their increased risk (10 to 15%) of conversion into malignant melanoma.
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Nevus /ne·vus/ pl. ne´vi [L.] 1. any congenital skin lesion; a birthmark. 2. a type of hamartoma representing a circumscribed stable malformation [more]Nevus - Community and Resources

Noun
1. a blemish on the skin formed before birth
(synonym) birthmark
(hypernym) blemish, defect, mar
(hyponym) port-wine stain, nevus flammeus

A pigmented spot on the skin, such as a mole. The plural of nevus is nevi.