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nevus ne·vus (nē'vəs)
n. pl. ne·vi (-vī')
A congenital circumscribed growth or mark on the skin, such as a mole or a birthmark, colored by hyperpigmentation or increased vascularity.
A benign localized overgrowth of melanin-forming cells arising in the skin early in life.
congenital skin lesion, or birthmark, caused by abnormal pigmentation or by proliferation of blood vessels and other dermal or epidermal structures. Nevi may be raised or may spread along the surface of the skin. In other types, such as the blue nevus, proliferative tissue is buried deep within the dermis, the lower layer of the skin