Approximately 75% of people of the Caucasian race have nevuses on their bodies (nevoid tumor). On average, an adult can count at least 20 nevi, and in some their number exceeds a hundred. In infancy and childhood, most of them are hardly noticeable, later they appear brighter due to the restructuring of the hormonal system during puberty, and in women during pregnancy. So what is it, nevus, we will understand together.

What is it, nevus?

Nevus (birthmark, birthmark) is a malformation of the skin, manifested in neoplasms on the skin, mucous membranes, conjunctiva, and membranes of the eyes, consisting of pigmented nevus cells. Some formations are congenital, appear during the period of fetal development of the fetus from the cells of the neural crest. They can reach sufficiently large sizes from 5 to 100 mm. Human DNA already contains information about congenital nevi: size, exact location. A newborn baby does not have noticeable pigment spots on the skin due to the small area of ​​the skin, but over the next few years they will certainly appear. Acquired nevi (pigmented cells under the epidermis) can appear on the human body throughout life under the influence of various factors.

What do the nevus look like

It is difficult to say for sure what the nevus looks like. Even scientists have not finally decided which formations to attribute to nevi and which to tumors.A mole that is the size of a pea with a diameter of 1 mm to a spot of 30 cm can protrude strongly over the skin, or merge with it, have a round or irregular shape with even or torn edges.

Types of Nevus

In connection with the variety of appearance, nevi are usually divided into several types.

Non-pigmented nevus

The pigmentless (basal) nevus is characterized by an oval shape of a white hue with smooth borders that do not protrude above the skin. The more a person spends time under the sun's rays, the more noticeably his skin darkens and the more pronounced non-pigmented nevi become. This kind of birthmark usually becomes noticeable in childhood and adolescence, does not disappear and does not change its size throughout life.

Depending on the localization of melanocyte cells, nevi are distinguished:

  • hypodermal (the pigment is located in the hypodermis, outwardly subtle);
  • borderline (melanin accumulated on the border between the dermis and epidermis);
  • intradermal (located directly in the dermis);
  • epidermal (the localization site is the epidermis, the upper layer of the skin).

Intradermal Nevus

Intradermal (dermal or intradermal) nevus is a benign neoplasm that most often stands out from the surface of the skin, but sometimes it can only differ in color from it. This type of mole is painless on palpation, has a soft surface and no inflammation around it. Its shade can be light pink, dark brown, sometimes black, which is quite rare.

Intradermal neoplasms are usually divided into:

  • warty;
  • pigmentary;
  • non-cellular.

Warty Nevus

The warty (papillomatous or verrucous) nevus in appearance is a dark brown growth with a tuberous surface, protruding above the skin. In most cases, it is congenital; in adulthood, it appears rather rarely, prevails in women. A congenital papillomatous mole, as a rule, is benign and, in addition to an aesthetic defect, does not carry discomfort to its owner. But if a dark growth is found in adulthood, it should be examined for malignancy.

Pigment nevus

Pigmented (melanocytic and melaniform) nevus is characterized by a high concentration of melanin in it, that is, a bright distinct color. The color of the melanocytic mole does not change over time and does not lose its brightness. Shape, size and surface can be completely different. Such neoplasms can most often be found in inaccessible places of the skin of a person: in the groin, armpits, under the mammary glands or between them.

Blue nevus

Blue nevus of Yadasson-Tiche is a type of melanocytic (pigmented) nevus; it differs in a color uncharacteristic for moles: from light blue to dark blue and violet. Blue moles are considered benign, but to some extent melanoma-hazardous (there are very few cases of degeneration).

Non-cellular nevus

Moles of non-cellular (fibroepithelial) type are located mainly in the face and neck, are a brown tubercle. The percentage of degeneration of non-extracellular nevuses into malignant melanoma is very small, therefore they should be removed only if they are a significant cosmetic defect.

Dysplastic nevus

The dysplastic variety of nevus is not similar to standard moles in external and internal parameters. They require a very attentive attitude, since the risk of a dysplastic nevus becoming a malignant type is very high.

Clinical manifestations of dysplastic nevus:

  • large size (at least 10 mm);
  • uneven color;
  • slight or no elevation above the skin;
  • uneven or torn edges;
  • thick and black hair.

Nevus Becker

This type of mole is mainly found in men at the age of puberty; its release is promoted by the release of androgens into the blood. Several small spots of light yellow color slowly increase in size and merge into a large spot with torn edges up to 20 cm in size. Becker nevus usually extends on the back, shoulders, in the pelvic area. In old age, the color intensity of such a mole decreases.

Nevus of the sebaceous glands

Nevus of the sebaceous glands (Yadasson's nevus) is a nodular benign neoplasm that appeared as a result of a malformation of the glands of the sebaceous secretion. This is mainly a congenital type of nevus, therefore it manifests itself in the first years of life in children of both sexes, most often on the scalp.

Nevus Setton

This is a type of pigmented nevus in which a patch of white skin forms around the mole. Setton's nevus appears in people of both sexes and at any age. Scientists associate it with autoimmune diseases, sometimes it is a harbinger of the development of vitiligo disease.

Nevus Unna

Unna Nevus (flaming or vascular nevus, wine stain, angel kiss, stork kiss) - a congenital birthmark on the face or neck, which is a consequence of a malformation of the vascular system in the prenatal period. With the growth of the child, the spot grows, the color becomes more intense over the years. Nevus Unna himself does not pass, but it is easy to treat with a laser.

Causes of nevi

Most nevi are considered congenital, that is, information about them is already available in the DNA of the newborn, and their manifestation is a matter of time. Scientists suggest that a defect in the development of the skin is laid in the last trimester of intrauterine development. Such neoplasms become more noticeable closer to 5 years of the baby's life, due to an impressive increase in the area of ​​the skin. Not the least role in the appearance of congenital nevi is played by the factor of heredity. Children, along with genetic material, inherit from their parents a chain of genes with chromosomes. The chances of passing your moles and birthmarks along with DNA to the children are 50/50% if the parent moles are congenital. Acquired nevi cannot be inherited.

Causes of acquired nevi:

  • ultraviolet irradiation contributes to an increase in the number of melanocytes in the blood, therefore, with constant exposure to the sun, in addition to a bronze tan, you can get pathology of the skin; women over 30 years of age are most sensitive in this matter;
  • hormonal surge during puberty, pregnancy, the development of diseases of the endocrine system contributes to the formation of new and the growth of existing moles and birthmarks;
  • trauma to the skin of any form leads to inflammation, which in turn stimulates active cell division; it can affect nevoid cells;
  • infection of the skin can cause an effect similar to trauma.

Histological examination of a mole

Even seemingly small nevi can be very dangerous and even fatal, but you should not rush to remove them all. If it became noticeable that the mole changes over time, grows, changes shape, itches, becomes inflamed, changes color, then it is impossible to postpone the trip to the oncodermatologist. Melanoma is a very serious illness, but it responds well to treatment in the initial stages.

The doctor should examine the neoplasms on the patient’s skin, find out how they changed, there is a hereditary predisposition to cancer in the family. If a doctor suspects a malignant type of nevus, a histological examination is required. This is the most advanced and accurate method of detecting cancer at an early stage. Under sterile conditions, a piece of mole tissue is excised and sent for analysis to the laboratory.According to the results of a histological examination of the nevus, it is possible to determine the type of neoplasm, the presence of malignancy and the stage of inflammation, if it is detected.

The risk of malignancy (malignancy) of nevi

Of all the aforementioned nevi, the most dangerous in terms of malignancy are dysplastic (of an unusual shape with torn edges and uneven color). Scientists believe that such a mole will sooner or later turn into a malignant tumor of the skin - melanoma.

A trauma to the process of malignancy of a mole can give an impetus to it: accidental one-time (wound, bruise, cut with a razor) or regular (if it constantly rubs against shoes, tight clothes). The relationship between the size of the mole and the risk of turning it into melanoma was revealed. If the nevus has reached a size of 2 cm in diameter, then the chances of malignancy are significant 20%. Moles on the face and neck are considered the most dangerous. If there are more than 20 moles on the human body, it is recommended to undergo an annual examination by a dermato-oncologist to ensure their good quality.

Treatment of nevi and methods for their removal

Treatment of benign nevi may be required only if they are a serious cosmetic defect. In other cases, the intervention is considered inappropriate and even undesirable, because it is the trauma of moles (it is difficult to be 100% sure of the qualifications of specialists, especially in regional medical institutions) that very often causes them to transform into a malignant tumor - melanoma.

If during the observation of a mole there is a change in its size, color, shape of the borders, inflammation, itching appears, the doctor raises the question of the need to remove it in one of the following ways:

  • Laser beam removal is the most popular method at the moment. This painless and short procedure will help remove a small nevus from any part of the patient’s body without leaving a scar, only a small depigmented spot;
  • surgical excision is the most affordable method, since it does not require specialized equipment, but leaves scars and is performed only under anesthesia, in childhood under general anesthesia;
  • cryodestruction allows you to quickly and painlessly remove a small neoplasm by completely freezing it, leaves no scars, but does not guarantee complete excision;
  • electrocoagulation - the destruction of nevus cells by exposure to directed electric current.

Dermato-oncologists strongly recommend not to resort to traditional medicine methods, since independent influence on nevi can lead to the most terrible and unpredictable consequences. Especially dangerous is the excision of a mole with a knife, razor or scissors on their own. It is believed that such trauma without subsequent treatment to a medical institution for treatment and treatment will lead to an increase in melanoma in almost 100% of cases.

Prevention of malignant nevus

You should not forget about the risk of malignancy of moles throughout your life. Their large sizes, having an irregular shape, it is desirable to examine a specialist and remove the method proposed by him. The remaining formations should be monitored so as not to miss their growth and modifications.

It is necessary to handle moles carefully, do not rub with a washcloth, do not expose to cosmetic procedures, and do not allow injuries!

If you accidentally hit or cut into the nevus, you should apply a sterile dressing and go to the doctor.

It is advisable not to expose the nevi to direct sunlight, cover them with clothing or a special adhesive plaster. Particular care must be taken when traveling on holidays to hot and sunny countries. Upon arrival home after rest, a mole should be examined for a long time for their modification.

Timely treatment of skin diseases is an important factor in the prevention of malignant degeneration of nevuses. If a rash, redness, peeling, burning, itching in the area of ​​a mole is detected, you should immediately consult a doctor and choose the most effective treatment method.

Very dry skin is also a factor predisposing to the development of melanoma, so it should be moisturized with special creams. In the presence of a constant syndrome of dry skin, you need to visit a doctor, pass tests if necessary, and choose more effective means. You may need to adjust the diet, supplementing it with vitamins and increased fluid intake.

Household chemicals, powders used by housewives at home and on production sites can adversely affect the condition of the skin and provoke a mutation of the nevus into malignant melanoma. In the presence of moles on the fingers and hands, dermatologists and oncologists recommend constantly using impervious gloves when washing dishes, floors, contaminated surfaces, and washing. Smoking tobacco products is considered one of the options for inhaling and swallowing dangerous chemical compounds, so nevus owners are advised to abandon this bad habit or reduce the dosage as much as possible.

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