nevus /ne·vus/ (ne´vus) pl. ne´vi [L.]
Nevus (plural, nevi)
nevus
nevus (nē´vus),
nevus
1. any congenital skin lesion; a birthmark.
2. a type of hamartoma representing a circumscribed stable malformation of the skin and occasionally of 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.
balloon cell nevus an intradermal nevus consisting of balloon cells with pale cytoplasm that contains large vacuoles formed of altered melanosomes.
blue nevus a dark blue nodular lesion composed of closely grouped melanocytes and melanophages situated in the mid-dermis.
blue rubber bleb nevus a hereditary condition marked by multiple bluish cutaneous hemangiomas with soft raised centers, frequently associated with hemangiomas of the gastrointestinal tract.
cellular blue nevus a large blue to blue-black, multilobulated, well-circumscribed, nodular tumor composed of melanocytes and spindle cells, tending to occur on the buttocks and sacrococcygeal region and having a low incidence of transformation to melanoma.
compound nevus a nevocytic nevus composed of fully formed nests of nevus cells in the epidermis and newly forming ones in the dermis.
connective tissue nevus any of a group of hamartomas involving various components of the connective tissue, usually present at birth or soon after.
dysplastic nevus an acquired atypical nevus with an irregular border, indistinct margin, and mixed coloration, characterized by intraepidermal melanocytic dysplasia and often a precursor of malignant melanoma.
nevus flam´meus a common congenital vascular malformation involving mature capillaries, ranging from pink (salmon patch) to dark bluish red (port-wine stain) and usually occurring on the face and neck.
giant congenital pigmented nevus , giant hairy nevus, giant pigmented nevus any of a group of large, darkly pigmented, hairy nevi, present at birth; they are associated with other cutaneous and subcutaneous lesions, neurofibromatosis, and leptomeningeal melanocytosis and exhibit a predisposition to the development of malignant melanoma.
halo nevus a pigmented nevus surrounded by a ring of depigmentation.
intradermal nevus a nevocytic nevus, 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 similar to nevus of Ota but localized to areas of distribution of the posterior supraclavicular and lateral cutaneous brachial nerves.
junction nevus a nevocytic nevus in which the nests of nevus cells are confined to the dermoepidermal junction.
nevus lipomato´sus nevolipoma.
nevocytic nevus , nevus cell nevus a tumor composed of nests of nevus cells, usually presenting as tan to brown small macules or papules with well-defined, rounded borders; they are subclassified as compound, intradermal, and junction.
nevus of Ota , Ota's nevus a mongolian spot–like lesion usually present at birth, involving the conjunctiva and lids, as well as adjacent facial skin, sclera, ocular muscles, periosteum, and buccal mucosa, usually unilaterally.
pigmented nevus a nevus containing melanin, usually restricted to nevocytic nevi and moles.
sebaceous nevus , nevus sebaceus of Jadassohn a syndrome characterized by single or linear hamartomas of the scalp, face, or neck that may change through life; neurologic symptoms and ophthalmic abnormalities may be present. Over time, some lesions become nodular and tend to develop benign or malignant adnexal tumors or basal cell carcinoma.
nevus spi´lus a smooth, tan to brown, macular nevus composed of melanocytes, and speckled with smaller, darker macules.
spindle and epithelioid cell nevus a benign compound nevus, seen usually in children, composed of dermal spindle and epithelioid cells, resembling malignant melanoma histologically and appearing as a smoothish, raised, firm, pink to purplish nodule or papule.
nevus spongio´sus al´bus muco´sae white sponge n.
nevus uni´us la´teris a verrucous epidermal nevus occurring as a linear band, patch, or streak, usually along the margin between two neuromeres.
vascular nevus , nevus vascula´ris, nevus vasculo´sus a reddish swelling or patch on the skin due to hypertrophy of the skin capillaries.
white sponge nevus a benign, congenital, inherited disorder characterized by extensive spongy whiteness and gray-white, soft, fissured lesions of the mucous membranes, especially of the oral mucosa.
ne·vus (n  v s)n. pl. ne·vi (-v   ) 1. A congenital circumscribed growth or mark on the skin, such as a mole or birthmark, colored by hyperpigmentation or increased vascularity. 2. A benign localized overgrowth of melanin-forming cells arising in the skin early in life. |
Nevus (plural, nevi)
The medical term for any anomaly of the skin that is present at birth, including moles and birthmarks.
nevus
[nē′vəs]
Etymology: L, naevus, birthmark
a pigmented skin blemish that is usually benign but may become cancerous. Any change in color, size, or texture or any bleeding or itching of a nevus merits investigation. Nevus is a benign tumor composed of nevus cells that are derived from melanocytes. Types include junction, compound, dermal, and congenital. Also spelled naevus. Also called birthmark, mole. See also blue nevus, junction nevus, nevus flammeus.
nevus (nē´vus),
n a circumscribed new growth of congenital origin that may be vascular (resulting from hypertrophy of blood or lymph vessels) or nonvascular (with epidermal and connective tissue predominating).
nevus, blue,
n a benign neoplasm characterized by heavily pigmented spindle cells deep in the tissue; appears clinically as a dark mole.
)
Blue nevus.
nevus, cellular pigmented,
n a nevus composed of melanin-producing “nevus” cells.
nevus, compound,
n a nevus in which the melanin-producing nevus cells are found in the epidermis and dermis: the intradermal nevus plus the junctional nevus.
nevus, intradermal,
n a nevus in which the melanin-producing nevus cells are found only in the dermis.
nevus, junctional,
n a nevus in which the melanin-producing nevus cells are found within the epidermis at the junction with the dermis.
nevus, pigmented,
n a dark-colored, benign neoplasm characterized by nevus cells. Junctional, intradermal, and compound types are recognized. Melanomas (malignant neoplasms) may develop from junctional or compound nevi.
nevus, white sponge (Cannon's disease; white folded gingivostomatitis),
n an inherited disease of the oral mucosa characterized by generalized white mucosal surfaces with a spongelike appearance.
)
White sponge nevus.
nevus
pl. nevi [L.] a circumscribed stable malformation of the skin and occasionally of 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; called also mole.
blue nevus
a dark blue nodular lesion composed of closely grouped melanocytes and melanophages situated in the mid-dermis.
connective tissue nevus
any nevus occurring in the dermal connective tissue and characterized by nodules, papules or plaques, or by combinations of such lesions. Histologically, there is inconstant focal or diffuse thickening and abnormal staining of collagen.
epidermal nevus
congenital skin tumors that do not contain melanocytes, which vary widely in appearance, size and distribution, and which are commonly hyperkeratotic.
hair follicle nevus
occur on the proximal extremities and have thick, brushlike hairs protruding.
intradermal nevus
a nevocytic nevus in which the nevus cells occur in nests in the upper part of the dermis, with no evidence of the proliferative process by which they originated.
melanocytic nevus
any nevus, usually pigmented, composed of melanocytes. See also melanoma.
pigmented nevus, nevus pigmentosus
one containing melanin; the term is usually restricted to nevocytic nevi (moles), but may be applied to other pigmented nevi.
sebaceous nevus
an epidermal nevus containing an overgrowth of sebaceous glands, frequently growing larger during puberty or early adult life, and rarely giving rise to a variety of new growths, including basal cell carcinoma.
nevus vascularis, nevus vasculosus, vascular nevus
a reddish swelling or patch on the skin due to hypertrophy of the skin capillaries. Seen on the scrotum of old dogs, sometimes bleeding.
naevus
Any localized area of pigmentation or vascularization of the skin or eye tissues, usually benign and congenital. Note: also spelt nevus. Plural: naevi.
choroidal naevus A benign accumulation of melanocytes in the choroid. It affects some 10% of the population. Ophthalmoscopically it appears as a slate-grey lesion, flat or minimally elevated, oval or circular. It is asymptomatic. With time drusen may also appear. See melanocyte; choroidal melanoma.
conjunctival naevus A naevus located on the conjunctiva, most often near the limbus. It appears as a yellowish-red area or deeply pigmented mass usually before the age of 20. A pigmented conjunctival naevus must be distinguished from an acquired melanoma of the conjunctiva which occurs later in life (after the third decade, is typically unilateral and may become malignant). A conjunctival naevus rarely becomes malignant. It can be excised if cosmetically undesirable or has enlarged to such a degree as to irritate the eye.
flammeus naevus See Sturge- Weber syndrome.
iris naevus A pigmented spot of variable size on the surface of the iris. It is composed of an accumulation of melanocytes in the iris stroma. It is usually benign but occasionally it may transform itself into a malignant melanoma. See melanocyte; iris melanoma; ICE syndrome.
naevus of Ota A benign, congenital, usually unilateral, accumulation of melanocytes on the cheek, eyelids, forehead, nose or sclera. Some naevi may become malignant melanoma. Syn. oculocutaneous melanosis; oculodermal melanocytosis. See ocular melanocytosis; melanosis.
choroidal naevus A benign accumulation of melanocytes in the choroid. It affects some 10% of the population. Ophthalmoscopically it appears as a slate-grey lesion, flat or minimally elevated, oval or circular. It is asymptomatic. With time drusen may also appear. See melanocyte; choroidal melanoma.
conjunctival naevus A naevus located on the conjunctiva, most often near the limbus. It appears as a yellowish-red area or deeply pigmented mass usually before the age of 20. A pigmented conjunctival naevus must be distinguished from an acquired melanoma of the conjunctiva which occurs later in life (after the third decade, is typically unilateral and may become malignant). A conjunctival naevus rarely becomes malignant. It can be excised if cosmetically undesirable or has enlarged to such a degree as to irritate the eye.
flammeus naevus See Sturge- Weber syndrome.
iris naevus A pigmented spot of variable size on the surface of the iris. It is composed of an accumulation of melanocytes in the iris stroma. It is usually benign but occasionally it may transform itself into a malignant melanoma. See melanocyte; iris melanoma; ICE syndrome.
naevus of Ota A benign, congenital, usually unilateral, accumulation of melanocytes on the cheek, eyelids, forehead, nose or sclera. Some naevi may become malignant melanoma. Syn. oculocutaneous melanosis; oculodermal melanocytosis. See ocular melanocytosis; melanosis.
nevus
Plural, nevi Dermatology An often congenital, usually benign, circumscribed pigmented–tan, brown, or flesh-colored, spot–eg, a mole, on the skin and/or mucosae, due to either an ↑ or ↓ of melanin; nevi are
considered hamartomas and contain spindle-shaped melanocytes. See Atypical nevus, Becker's nevus, Blue nevus, Congenital nevus, Dysplastic nevus, Familial dysplastic nevus, Garment nevus, Giant (pigmented) hairy nevus, Halo nevus, IVLEN nevus, Malignant blue nevus, Melanocytic nevus, Port-wine nevus, Speckled lentiginous nevus, Spitz nevus, Spotted pigmented nevus, White sponge nevus. Cf Lymph node inclusions.
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