The skin is considered the largest organ in humans. It protects tissues and organs from physical damage, high temperatures and chemicals. As you know, skin color is different. First of all, it depends on the race, the genetic characteristics of the organism, as well as on environmental conditions. The color of the skin is provided by special cells - melanocytes. Normally, they are located evenly in the basal layer of the epidermis. However, in some areas, a large accumulation of melanocytes is found. This is visible to the naked eye. Areas of the skin with accumulations of melanin cells are called pigmented nevi. Such formations are familiar to everyone. They are called moles or age spots. The sizes of such formations can vary. They also differ in color intensity: from light brown to deep black.
Pigmented nevus: what is it, photo
It's no secret that almost everyone has moles on their skin. Nevertheless, not everyone knows that a synonym for these formations is "pigmentednevus". However, this concept is much broader. It includes not only small moles, but also age spots that reach large sizes. Nevi can be located on the skin, as well as on the mucous membranes and even on the iris of the eye. Formations consisting of melanocytes differ in size, thickness, shape and color. So what is a pigmented nevus? Photos of such formations can be found in the special literature on dermatology, cosmetology or oncology. Viewing images of various nevi will help you get an idea of their types. Despite this, in order to verify the origin of the mole, it is necessary to consult a specialist.
In most cases, pigmented skin nevi appear in early childhood. Small brown formations that slightly rise above the surface of the epidermis are called moles. They grow almost imperceptibly and do not disturb the baby in any way. Birthmarks are also referred to as nevi. These formations are larger and of different shapes. They rarely rise above the surface of the skin. A child is born with these age spots, and they grow with him.
All nevi are made up of a pigment called melanin, which gives color to our skin, iris and hair. The amount of this substance varies. The pigment content in the body is higher in dark-haired and swarthy people. The accumulation of melanin in one place leads to the formation of nevi. They can be located anywhere, including on internal organs and muscles. Pigmentary nevus isbenign neoplasm, which normally does not bother a person. Most often, birthmarks are not subject to treatment if they do not cause aesthetic discomfort. A few years ago, it was believed that small pigmented formations on the face, on the contrary, give beauty. It is currently known that not all moles are safe. In cases where there is a risk of malignancy of a benign neoplasm, it should be removed.
Causes of nevi
All pigmented skin nevi can be conditionally divided into congenital and acquired. This classification is not scientifically sound, as it is still unknown when exactly the clusters of melanocytes are formed. This division is based only on the time of appearance of nevi. If areas of the skin acquire a dark color in early childhood, then the formations are considered congenital. Acquired nevi appear in adolescents or adults.
The causes of congenital age spots are unknown. It is believed that the pathological migration of melanoblasts occurs even during fetal development. Risk factors include illness during pregnancy, medication or other chemical exposures, and hormonal imbalances. A possible cause of congenital nevi is a genetic predisposition. This explains the appearance of "Mongolian spots" in children of Asian origin.
Acquired nevi are considered more dangerous, since the frequency of transformation of these neoplasms into a cancerous tumor is higher. However, according to other data,all areas of pigmentation are formed at the stage of fetal development, and their appearance indicates the adverse effects of provoking factors. Regardless of this, the following causes of nevi are distinguished:
- Hormonal changes in the body.
- Infection of the skin.
- Solar insolation.
- Visit solarium.
- Skin damage.
In fact, the allocation of such provoking factors is quite justified. Hormonal imbalance develops during puberty and pregnancy. During these periods, the incidence of moles is much higher. In addition, age spots often appear in women using hormonal contraceptives.
Chronic skin pathologies (atopic dermatitis, acne) and physical damage often provoke the appearance of pigmented nevi on the face, neck and shoulder area. The main reason for the appearance of moles is solar insolation. Exposure to ultraviolet radiation not only affects the occurrence of pigmentation, but also increases the risk of malignancy of formations. Therefore, people with problem skin should not be exposed to direct sunlight for a long time.
Classification of pigmented formations
According to the histological structure, about 50 varieties of nevi are distinguished. Of these, the most significant are 10 types of benign formations that differ in origin and clinical picture. Doctors distinguish 2 main groups of nevi, each of which includes several types of age spots. The basisclassification put the risk of malignancy education. The first group includes melanogenic nevi. The risk of malignancy of such formations is small. These include the following types of age spots:
- Papillomatous nevus. It differs in that it looks like melanoma: it has an uneven, bumpy surface and rises above the surface of the skin. The hair on this formation continues to grow, but changes color. Papillomatous nevus has a dark brown tint. Localization of such a mole is the trunk, limbs and scalp.
- Mongolian spot. It has various shapes and large sizes. This congenital pigmented nevus occurs in most children of the Mongoloid race. It does not rise above the epidermis and disappears on its own by the age of 20.
- Galonevus - refers to acquired benign skin lesions. It has an oval or round shape. The peculiarity of this mole is that there is a light rim around it. Such a formation can be located on any part of the skin or on the mucous membranes. With age, the mole brightens and disappears.
- Intradermal pigmented nevus. It is characterized by small size and peculiar localization: neck area and skin folds. It appears most often in puberty. Under the influence of adverse factors, it can malignize into melanoma. A complex pigmented nevus has a similar structure. It is a small pigmented formation resembling a papule.
- Fibroepithelial nevus. This formation consists of connective tissue and rarelyundergoes degradation. It protrudes significantly above the surface of the skin, has a light brown or pinkish tint. Such a mole has a rounded shape and a smooth surface. Education can be congenital, but more often occurs in older people.
Melaninous nevi are rarely malignant, but they require observation. The absence of growth of such moles indicates a favorable prognosis.
Melanoma skin nevi
Melanoma-dangerous nevi include benign neoplasms of the skin, the probability of malignancy of which is high. Therefore, they require constant monitoring or radical treatment. Such age spots include the following formations:
- Yadasson's blue nevus - Tiche. Despite the fact that it consists of differentiated pigment cells, pathology refers to precancerous conditions. The blue nevus is small (up to 1 cm) and slightly protrudes above the surface of the epidermis. In some cases, it is represented by a nodule located in the thickness of the skin. The formation is purple or dark blue in color.
- Border pigment nevus. Refers to congenital formations. Such a mole protrudes above the surface of the skin and has a dark color. The color of the pathological area may be purple, brown or dark gray. The size of the nevus does not exceed 1.2 cm. The name of this formation is due to the fact that the pigment cells of which it consists are located on the border of the epidermis and dermis.
- Giant nevus. Giventhe pigment spot is large (more than 20 cm) and can occupy a significant area of the body. The giant nevus has a rough surface and a dark color. Increased hair growth is noted on the pathological area of the skin.
- Nevus Ott. A disease characterized by the presence of bluish spots on the skin of the face, lips, mucous membranes of the eye. It is often a birth defect, but can also occur during adolescence. The risk of developing such a disease is significantly increased among representatives of the Mongoloid race.
- Clark's nevus. It is characterized by asymmetry of contours, a flat surface and various colors. The size of the skin defect ranges from 5 mm to 6 cm. The nevus can be located in the back, along the back of the thighs, or around the genitals. It belongs to dysplastic formations, which are highly likely to transform into oncological pathology.
Melanoma-dangerous nevi are an extensive group of pathological conditions that require diagnosis and treatment. In some cases, when removal of the formation is impossible, constant prevention of malignancy is necessary.
Nevus of the eye: features
The accumulation of melanocytes is observed not only on the skin, but also on the mucous membranes. An example is the pigmented nevus of the eye. Another name for this formation is a benign tumor of the choroid. It refers to congenital pathologies, but begins to manifest itself only by 10-12 years. This is due to the fact that at this age there is an increasedpigment formation. There are 3 types of choroidal nevi:
- Stationary.
- Progressive.
- Atypical.
They all belong to benign tumors of the eye, however, under the influence of provoking factors, they tend to become malignant. Like skin lesions, choroidal tumors are characterized by discoloration. So, what is it - pigmented nevi of the eye? Photos of such tumors are presented in abundance in the literature for ophthalmologists and oncologists, as well as on medical sites. Nevi are small spots in the eye that differ in color from the color of the iris.
Types of choroid tumors
Stationary nevus of the eye is characterized by clear or pinnate contours. It has a greenish or gray color. The shape, size and color of the formation do not change during life. Such tumors are practically not malignant.
Progressive nevus is different in that it has a yellow rim around the main accumulation of pigment. The color and shape of the defect may change. In addition, such nevi increase in size, which increases the risk of vascular compression and reduced visual fields. Therefore, with this type of pathology, medical supervision is required.
Atypical nevi have a poor prognosis. Therefore, at the slightest change or growth, urgent surgical treatment is required. Such formations are light in color and are accompanied by visual impairment.
Diagnosis of pigmented tumors
In case of changes in the nevus or itsappearance, you should consult an oncologist. He will be able to make a differential diagnosis between various skin neoplasms and choose treatment tactics. An important study is dermatoscopy, which allows you to see the pigment spot under high magnification. If malignancy of the tumor is suspected, a complete laboratory diagnosis, X-ray of the chest organs and ultrasound of the abdominal cavity are performed. To establish the histological type of the nevus, a wide excision of the formation is performed. A biopsy is performed only in emergency situations, as it can lead to malignancy and the spread of tumor cells.
Pigmented nevus: treatment
Photos depicting nevi can be found in many sources of relevant topics. Nevertheless, only a doctor can definitively determine what kind of tumor it is. Treatment of pigmented nevi is not always carried out. In cases where the mole is harmless and does not cause cosmetic discomfort, dynamic observation is indicated. Nevi are subject to removal, which are often traumatized. You can remove the formation with liquid nitrogen or a laser. If there is a risk of malignancy, surgical removal of pigmented nevi is required. At the same time, they recede from the spot by 2 cm and capture he althy tissues. The resulting material is sent to a histological laboratory.
Possible complications of nevi
The main complication of nevi is the transformation of normal pigment cells into melanoma. Allocatethe following signs of malignancy:
- Sudden growth in education.
- Bleeding or ulceration.
- Changing the color of a mole.
- Pain.
- Itching and burning.
If you have any of these symptoms, you should immediately contact an oncologist and remove the formation. Only timely surgical treatment will help to avoid cancer.
Prevention of malignant skin lesions
To prevent pigment spots from becoming malignant, all possible risk factors should be excluded. This is especially true for exposure to the sun and traumatization of nevi. People who have moles on their body are not recommended to sunbathe and visit the solarium.
Melanoma prevention methods include dynamic monitoring by an oncologist, as well as timely removal of dangerous nevi.
