| nevus cell | The cell of a pigmented cutaneous nevus that differs from a normal melanocyte in that it lacks dendrites. A-type, melanocytes in the epidermis in pigmented nevi, resembling epithelial cells and frequently containing melanin. Nevus cell, B-type, small, usually non-pigmented melanocytes in the mid-dermis in pigmented nevi. Nevus cell, C-type, non-pigmented spindle-shaped melanocytes in the lower dermis in pigmented nevi. Synonym: nevocyte. (05 Mar 2000) |
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| nevus comedonicus | Comedo nevus, congenital or childhood linear keratinous cystic invaginations of the epidermis, with failure of development of normal pilosebaceous follicles. Synonym: nevus follicularis keratosis. (05 Mar 2000) |
| nevus elasticus of Lewandowski | An obsolete term for plaques of smooth or nodular papules, skin-or ivory-coloured, occurring symmetrically on the trunk or extremities; now known to be a collagenous nevus. (05 Mar 2000) |
| nevus, epithelioid and spindle cell | 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. The tumour presents as a smooth to slightly scaly, round to oval, raised, firm papule or nodule, ranging in colour from pink-tan to purplish red, often with surface telangiectasia. (12 Dec 1998) |
| nevus flammeus | Flame nevus, a large congenital vascular nevus having a purplish colour; it is usually found on the head and neck and persists throughout life. See: Sturge-Weber syndrome. Synonym: port-wine mark, port-wine stain. (05 Mar 2000) |
| nevus follicularis keratosis | Comedo nevus, congenital or childhood linear keratinous cystic invaginations of the epidermis, with failure of development of normal pilosebaceous follicles. Synonym: nevus follicularis keratosis. (05 Mar 2000) |
| nevus, intradermal | A nevus in which nests of melanocytes are found in the dermis, but not at the epidermal-dermal junction. Benign pigmented nevi in adults are most commonly intradermal. (12 Dec 1998) |
| nevus lipomatodes | Unsatisfactory terms for a lesion that is basically a melanocytic nevus, mixed adipose cells in the dermis. Synonym: nevus lipomatodes, nevus lipomatosus. Origin: nevus + lipoma (05 Mar 2000) |
| nevus lymphaticus | A cutaneous lymphangioma. (05 Mar 2000) |
| nevus of ota | A macular lesion on the side of the face, involving the conjunctiva and lids, as well as the adjacent facial skin, sclera, ocular muscles, and periosteum. Histological features vary from those of a mongolian spot to those of a blue nevus. (12 Dec 1998) |
| nevus papillomatosus | A prominent wartlike mole. (05 Mar 2000) |
| nevus, pigmented | A nevus containing melanin. The term is usually restricted to nevocytic nevi (round or oval collections of melanin-containing nevus cells occurring at the dermoepidermal junction of the skin or in the dermis proper) or moles, but may be applied to other pigmented nevi. (12 Dec 1998) |
| nevus pigmentosus | A benign pigmented melanocytic proliferation; raised or level with the skin, present at birth or arising early in life. Synonym: mole. (05 Mar 2000) |
| nevus pilosus | A mole covered with an abundant growth of hair. Synonym: hairy mole. (05 Mar 2000) |
| nevus sanguineus | <dermatology> Red or purple-coloured vascular skin markings that develop shortly after birth. Most are usually painless and benign and sharply demarcated from surrounding skin, usually located on the head and neck, and grow rapidly. It is caused by proliferation of immature capillary vessels in active stroma, and is usually present at birth or occurs within the first two or three months of life. Some lesions (cavernous haemangioma) will disappear or become harder to see as the child approaches school age. Localised steroid injections have been used successfully to reduce the size of a birthmark but generally they undergo spontaneous regression and involution without scarring and normally require no treatment. (07 Mar 2000) |