1. A circumscribed malformation of the skin, especially if colored by hyperpigmentation or increased vascularity.

A nevus may be predominantly epidermal, adnexal, melanocytic, vascular, or mesodermal, or a compound overgrowth of these tissues.

2. Any lesion containing melanocytes; any birthmark; mole.
3. A congenital discoloration of a circumscribed area of the skin as a result of pigmentation.
4. A circumscribed vascular tumor of the skin, usually congenital, due to hyperplasia of the blood vessels.
5. A benign pigmented spot on the skin; such as, a mole (a cluster of melanocytes and supportive tissue that appears as a tan, brown, or flesh-colored spot on the skin).
6. A benign blood vessel tumor on the skin; such as, a vascular nevus, a local collection of capillaries of the skin (a strawberry birthmark, stork mark, or port wine stain).
7. Etymology: from the Latin naevus meaning "a body mole"; especially, "a birthmark".

A melanocytic nevus that is not visible at birth, but appears in childhood or adult life.

A nevus in which many of the cells are large, with clear cytoplasm.

A nevus is a birthmark, mole, or any other kind of growth or mark on the skin that a person is born with.

A hereditary disease noted in infancy or adolescence, characterized by lesions of the eyelids, nose, cheeks, neck, and axillae, appearing as uneroded flesh-colored papules, some becoming pedunculated, and histologically indistinguishable from basal cell epithelioma.

A dark blue nevus covered by smooth skin.

It is composed of melanin-pigmented spindle cells in the mid-dermis.

An erectile, easily compressable, bluish, cavernous hemangioma that is present in the skin and gastrointestinal tract.

A nevus of dilated capillary vessels elevated above the skin.

It is usually treated by ligature (thread used to tie something) and excision (cut out).

A nevus composed of collagenous tissue; which is, any of a class of extracellular proteins abundant in higher animals; especially, in the skin, bone, cartilage, tendon, and teeth, forming strong insoluble fibers and serving as connective tissue between cells. It yields gelatin when denatured by boiling.

A nevus formation on the skin.

Raised lesions present at birth. They may be hyperkeratotic (horny layer of the skin) and widely distributed.

A nevus covered by a heavy growth of hair. It is usually darkly pigmented.

A nevus in which the melanocytes (epidermal cells that give skin its color) are found in nests in the dermis and have no connection with the deeper layers from which they were formed.

A pale vascular birthmark found on the nape of the neck in 25-50 percent of normal people.

A common mole.

Moles may appear at any age. They are classified according to their stage of growth and whether or not they are still growing.

A kind of swollen blood vessels just below the surface of the skin; spider naevus; spider angioma: Nevus araneus usually contains a central red spot with extensions that are a deep reddish color radiating outwards and resembling a spider's web.

A horny nevus that contains a hard plug of keratin (horn-like protein in the upper layer of the skin).

It is caused by failure of the pilosebaceous follicles (hair follicles and sebaceous glands) to develop normally.

1. A large congenital vascular malformation nevus having a purplish color.

It is usually found on the head and neck and persists throughout life.

2. A large reddish-purple discoloration of the face or neck, usually not elevated above the skin.

It is considered a serious deformity due to its large size and color. In children, these have been treated with the flashlamp-pulsed tunable dye laser.

Congenital papillary acanthosis of the epidermis, with hyperplasia of sebaceous glands developing at puberty and presence of apocrine glands in nonapocrine areas of the skin (commonly the scalp).

A variety of epithelial tumors may arise from a nevus sebaceus in adult life, most commonly basal cell carcinoma.

A pigmented nevus with a smooth, unraised surface.

A congenital systematized linear nevus limited to one side of the body or to portions of the limbs on one side.

Lesions are often extensive, forming wavelike bands on the trunk and spiraling streaks on the limbs.

A nevus in which superficial blood vessels are enlarged.

A nevus in which superficial blood vessels are enlarged. Nevi of this type are usually congenital.

They are of variable size and shape, slightly elevated, and red or purple in color. They generally appear on the face, head, neck, and arms, though no region is exempt. The nevi usually disappear spontaneously, but wrinkling, pigmentation, and scarring are sometimes seen.

An epidermal nevus containing sebaceous gland tissue.

A skin-colored or darker wartlike, often linear lesion appearing at birth or early in childhood and occurring in various sizes and locations, single or multiple.