Birthmarks (melanocytic or nevoid education nevi) - limited pigmented spots or nodules, consisting of clusters of melanocytes (cells containing the pigment melanin, they are also a lot of people in the skin of black and yellow races) or nevus cells.
Almost every person has a certain amount of moles, which usually appear in childhood and adolescence.They come in various sizes and colors (flesh, yellowish-brown, black);flat or raised above the skin;smooth, hairy or warty;with a broad base, or sitting on the "stalk".
At puberty and during pregnancy may appear new birthmarks and existing sometimes increase or darken.About 40-50% of malignant melanomas develop from melanocytes nevi (the rest - melanocytes from normal skin);in children, these tumors are very rare and come from large pigmented nevi, available from birth.
1. Lentigo - is uniformly flat pigmented spot of the brown-brown to black in color, which result from increasing the number of melanocytes at the border of the epidermis and dermis (skin
2. Epidermis-dermal nevi usually flat, but sometimes a few rise above the skin.Coating varies light brown to nearly black, sizes - from 1 to 10 mm in diameter.Result from the accumulation of melanocytes at the boundary between the epidermis and dermis.Birthmark on the palms, soles and in the genital area are usually the epidermal-dermal.
3. Sophisticated nevi often have a dark color and more or less raised above the skin.Clusters of melanocytes localized (are) on the boundary between the epidermis and dermis, and in the dermis.
4. Intradermal nevi raised above the skin;their coloration varies from body to black, and the surface may be smooth or hairy wart.As melanocytes and nevus cells, almost all are localized in the dermis.
5. Nevus Sutton - a pigmented birthmarks (usually complex and intradermal nevi), surrounded by a ring of depigmented (unpainted) of the skin.Sutton's nevi disappear spontaneously and only rarely give rise to malignant melanoma.
6. dysplastic nevi - a pigmented spots with irregular shapes and blurred, slightly above the level of the skin, their color varies from tan to dark brown on a pink background.Dysplastic nevi first attracted the attention of their unusual appearance and increased frequency in some families (inherited).
As a rule, they are larger than ordinary birthmarks, reaching 5-12 mm in diameter;localization and different: dysplastic nevi, although they can occur anywhere, are more common in areas normally closed clothes (on the buttocks, breasts), or on the scalp.Most people have an average of 10 ordinary moles, whereas dysplastic nevi may be more than 100. Common nevi usually appear before the onset of maturity, dysplastic however, continued to occur even after 35 years.