[ne´vus] (pl. ne´vi) (L.)
a circumscribed stable malformation of the skin or sometimes the oral mucosa, which is not due to external causes; the excess (or deficiency) of tissue may involve epidermal, connective tissue, adnexal, nervous, or vascular elements. Most are either brown, black, or pink; they may appear on any part of the skin, vary in size and thickness, and occur either in groups or alone. See also
A nevus is usually not troublesome unless it is unsightly or disfiguring or becomes inflamed. If it changes noticeably, malignancy may be suspected, especially if any of the following are present: a highly irregular border, an uneven (pebbly) surface, or a mixture of colors (especially black, gray, or blue). Any change in size, color, or texture, or any bleeding or excessive itching, should be reported to a health care provider. Nevi can be removed by surgery or by other methods such as the application of solid carbon dioxide, injections, or radiotherapy.
blue rubber bleb nevus
a hereditary condition marked by multiple bluish cutaneous
with soft raised centers, frequently associated with
of the gastrointestinal tract.
a rare epidermal nevus marked by one or more patches 2 to 5 cm or more in diameter, in which there are collections of large comedones or comedolike lesions. This condition is occasionally associated with other lesions such as
composed of fully formed nests of nevus cells in the epidermis and newly forming ones in the dermis.
connective tissue nevus any nevus found in the dermal connective tissue with nodules, papules, plaques, or combinations of such lesions. Histologically, there is inconstant focal or diffuse thickening and abnormal staining of collagen.
epidermal nevus (epithelial nevus) a circumscribed congenital developmental anomaly resulting in faulty production of mature or nearly mature cutaneous structures; such nevi vary widely in appearance, size, and distribution and are commonly hyperkeratotic.
a congenital vascular malformation involving mature capillaries, present at birth. It consists of a reddish purple lesion that is flat or barely elevated and does not fade with age. It is a benign condition but may be associated with other syndromes such as
. The dark variety is called a
and a light variety is called a
. (See Atlas 1, Part E).
giant congenital pigmented nevus (giant hairy nevus) (giant pigmented nevus) any of a group of large, darkly pigmented hairy nevi, usually bilaterally symmetrical and present at birth; the most common locations are the chest, upper back, shoulders, arms, legs, and or hip and groin area. These nevi are associated with other cutaneous and subcutaneous lesions, as well as neurofibromatosis and other developmental anomalies, and they exhibit a predisposition to development of malignant melanoma.
a type of
clinically indistinguishable from compound nevus, in which the nests of nevus cells lie exclusively within the dermis.
nevus of Ito
a mongolian spot–like lesion having the same features as
except for localization to the areas of distribution of the posterior supraclavicular and lateral cutaneous brachial nerves, involving the shoulder, side of the neck, supraclavicular areas, and upper arm.
junction nevus (junctional nevus) a brownish, smooth, flat or slightly raised nevocytic nevus; histologically, there are nests of melanin-containing nevus cells at the dermoepidermal junction. (See Atlas 2, Part N.)
nevus lipomato´sus one that contains much fibrofatty tissue.
any nevus, usually pigmented, composed of
nevus cell nevus
) the most common type of nevus, usually more or less hyperpigmented, initially flat but soon becoming elevated, composed of nests of nevus cells. These nevi are classified as compound, intradermal, or junction according to the histologic pattern and location of nevus cells. Called also
nevus of Ota
) a persistent mongolian spot–like lesion, usually present at birth and unilateral, involving the conjunctiva and skin about the eye, as well as the sclera, ocular muscles, retrobulbar fat, periosteum, and buccal mucosa. It is a blue or gray-brown patchy area of pigmentation that grows slowly and becomes deeper in color. Although the lesion is benign,
occasionally develops, usually in the iris.
) one containing
; the term is usually restricted to
(moles), but may be applied to other nevi that have pigmentation.
nevus sebaceus of Jadassohn
) an epidermal nevus of the scalp or less often the face, frequently growing larger during puberty or early adult life. In later life, some lesions may give rise to a variety of new growths, including
a smooth, tan to brown, macular nevus composed of
and speckled with smaller, darker macules.
spindle and epithelioid cell nevus a benign compound nevus occurring most often in children before puberty, composed of spindle and epithelioid cells located mainly in the dermis, sometimes in association with large atypical cells and multinucleate cells, and having a close histopathological resemblance to malignant melanoma.
nevus uni´us la´teris a wartlike epidermal nevus, ranging from flesh colored to brown, found in a linear, unilaterally distributed pattern; on the extremities, the lesions usually follow the long axis, and on the trunk, they usually have a transverse orientation.
white sponge nevus a spongy white nevus of a mucous membrane, occurring as a hereditary condition.
a telangiectatic arteriole in the skin with radiating capillary branches simulating the legs of a spider; characteristic, but not pathognomonic, of parenchymatous liver disease; also seen in pregnancy, often disappearing after delivery, and at times in healthy people.
A superficial spider-like cluster of capillaries composed of a central ‘feeder’ vessel and multiple minute tortuous and dilated radiating vessels with a peripheral erythaema; when the involved vessel is large, it may pulsate and blanch on pressure; while classically due to increased circulating oestrogens as seen in pregnancy and alcoholic cirrhosis, SAs may occur in chronic hepatic congestion 2º to constrictive pericarditis and may be a normal birthmark in children
A telangiectatic arteriole in the skin with radiating capillary branches simulating the legs of a spider; characteristic, but not pathognomonic, of parenchymatous liver disease; also seen in pregnancy, often disappearing after delivery, and at times in otherwise healthy people.
(ne’vus) (ne’vi?) plural.nevi [L. naevus, birthmark] 1.
A congenital discoloration of a circumscribed area of the skin due to pigmentation. Synonym:
A circumscribed vascular tumor of the skin, usually congenital, due to hyperplasia of the blood vessels. See:
A patch of pale skin in which blood vessels are narrowed or contracted and blood flow is locally limited.
A dark blue nevus covered by smooth skin. It is composed of melanin-pigmented spindle cells in the mid-dermis.
blue rubber bleb nevus
An erectile, easily compressible, bluish, cavernous hemangioma present in the skin and gastrointestinal tract.
A nevus of dilated capillary vessels elevated above the skin. It is usually treated by ligature and excision.
A horny nevus that contains a hard plug of keratin. It is caused by failure of the pilosebaceous follicles to develop normally.
A cluster of melanocytes found in both the epidermis and the dermis.
connective tissue nevus
A nevus composed of collagenous tissue.
A nevus formation on the skin.
A nevus composed of cells having some malignant characteristics.
A benign nevus often found on the scalp, having a pale or tan center enclosed within a darker encircling rim.
Raised nevi present at birth. They may be hyperkeratotic and widely distributed.
faun tail nevus
In newborns, a tuft of hair over the lower spinal column. It may be associated with spina bifida occulta.
A large reddish-purple nevus 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.
A nevus covered by a heavy growth of hair. It is usually darkly pigmented.
A papular brown nevus with an oval halo occurring in the first three decades of life. This type of nevus is usually benign but should be evaluated for malignancy.
A nevus in which the melanocytes are found in nests in the dermis and have no connection with the deeper layers from which they were formed.
See: Ito nevus
A nevus in the basal cell zone at the junction of the epidermis and dermis. It is slightly raised, pigmented, and does not contain hair. This type of nevus may become malignant. See: illustration
A tumor composed of fatty connective tissue. It is probably a degenerated nevus containing numerous blood vessels.
Any nevus that contains melanocytes.
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.
See: Ota nevus
A congenital nevus varying in color from light yellow to black. Intradermal or nevocytic nevi are benign. Other types of nevi may become malignant. Synonym:
Malignant or suspicious lesions should be treated by wide surgical excision. Benign lesions do not require treatment except when located at sites of friction causing bleeding or ulceration. Some nevi are removed for cosmetic reasons.
An epidermal nevus containing sebaceous gland tissue.
Synonym: sebaceous nevus
A pigmented nevus with a smooth, unraised surface.
nevus spongiosus albus mucosae
1. Vascular nevus.
2. Infantile hemangioma.
A nevus containing dilated capillaries.
nevus unius lateris
A congenital nevus that occurs in streaks or linear bands on one side of the body. It usually occurs between the neurotomes of the lumbar or sacral area.
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.
Synonym: strawberry nevus (1); nevus vascularis
A nevus formed of dilated venules.
Synonym: nevus venosus
A nevus with a raised, wartlike surface.
Synonym: nevus verrucosus
white sponge nevus
A white, spongy nevus that may occur in the mouth, labia, vagina, or rectum. Synonym: nevus spongiosus albus mucosae