home Calculators Nevus: causes, types, diagnosis, treatment. Are pigmented moles dangerous? Other nevus-like formations

Nevus: causes, types, diagnosis, treatment. Are pigmented moles dangerous? Other nevus-like formations

Thank you

Nevus(pigmented spot, pigmented nevus, melanocytic nevus) is a benign neoplasm, which in most cases is a congenital malformation of the skin. In a limited area, a cluster of special cells - nevocytes - is formed, which contain a large amount of melanin pigment. Nevocytes are pathologically altered melanocytes - cells that normally synthesize melanin and give color to the skin. Noncellular nevus is a synonym for pigmented nevus.
Mole and nevus are also identical concepts (the term itself comes from Latin word naevus – “birthmark”).

Melanin and melanocytes

Melanin– a natural pigment (dye) that is found in human skin, hair, retina and iris, and in the brain. It is the amount of melanin that determines the intensity of the color of a person’s skin, the color of his eyes, and the ability to tan.

There are three types of melanin:

eumelanin – has a brown or black color;
pheomelanin – yellow color;
Neuromelanin is a special type of pigment found in the brain.

The place of melanin formation in the skin are melanocytes - specialized cells that have many processes. They capture thyroxine from the blood, a hormone secreted by the thyroid gland. After oxidation, thyroxine turns into melanin. Then it is transported along the processes of melanocytes to skin cells and deposited in them.

Melanin is not just a pigment. It performs many other functions in the body:

it is a powerful antioxidant: it protects cells from damage by certain toxic substances, radioactive and other radiation;
increases the body's resistance to stress;
stabilizes emotional background, prevents excessive emotionality;
takes part in the regulation of sleep and wakefulness processes.

With albinism, a hereditary disease, the human body is completely devoid of melanin. It is known that albinos are much more susceptible to various diseases.

Causes of nevi

Many researchers are inclined to think that absolutely everything pigmented nevi, even those that appear with age are birth defects skin development. Disorders that lead to the formation of this benign tumor, arise in the embryonic state of the body.

To date, not all have been studied congenital causes formation of dysplastic nevi.
The main factors include:

Fluctuations in the level of sex hormones in the body of a pregnant woman: progestins and estrogens.
Infections genitourinary system in pregnant women.

Impact on the body of a pregnant woman unfavorable factors: toxic substances, radiation.
Genetic disorders.

Under the influence of all these factors, the development of melanoblasts, the cells from which melanocytes are subsequently formed, is disrupted. As a result, melanoblasts accumulate in certain areas of the skin and transform into nevocytic cells.

Nevocytes differ from normal melanocytes in two ways:
1. They do not have processes through which the pigment could spread to other skin cells;
2. Dysplastic nevi obey the general regulatory systems of the body worse, but, unlike cancer cells, have not completely lost this ability.

It is believed that with age, new pigmented nevi do not appear, but only those that existed from birth, but were not noticeable, manifest themselves.

The following reasons can initiate the manifestation of new melanocytic nevi:

Hormonal changes in the body. This is very clearly shown in adolescence when it appears on the body most of nevi.
Effect of ultraviolet rays on the skin. Frequent sunbathing and solariums contribute to the growth of age spots.
Pregnancy. As noted above, this is due to fluctuations in the level of sex hormones in a woman’s body.
Taking contraceptives.
Inflammatory and allergic diseases skin (acne, dermatitis, various rashes).

Symptoms and classification of nevi

Melanocytic nevi come in a wide variety of shapes, colors and sizes. Until now, there is no clear opinion among doctors about which formations should be designated by the word “nevus”. Therefore, benign skin tumors that do not contain the pigment melanin are sometimes called nevi:

Hemangiomas– vascular tumors. The concept of “strawberry nevus” is especially common - a red hemangioma, which is present in most newborns and disappears during the first year of life. Also, many doctors operate with such a concept as vascular nevus.
Nevi sebaceous glands – in most cases located on the head, they also do not contain melanin. This growth is known as a sebaceous nevus.
Sometimes congenital nevi in children are also called teratomas (hamartomas) , which, in fact, are congenital tumors consisting not only of the skin, but also of all other tissues.
Anemic nevus– a type of vascular nevus. This is an area of the skin where blood vessels are underdeveloped, so it has a lighter color.

A true melanoform nevus is a formation that occurs from altered melanocyte cells - nevocytes.

Distinguish the following types nevi:
1. Noncellular border nevus - a simple spot that does not rise on the skin, or slightly protrudes above its surface. A border nevus has clear contours and a brown color. It can have different sizes and be located on different parts bodies. With this type of melanoform nevus, a cluster of cells with pigment is located between the upper (epidermis) and middle (dermis) layers of the skin - this location is referred to as an intraepidermal nevus.
2. Intradermal nevus – the most common type of melanoform nevus. It is so called because the accumulation of pigment cells is located in the thickness of the middle layer of the skin - the dermis.
3. Pigmented complex nevus of the skin. This nevus looks like a mole: it rises on the skin and can have a different color, from light brown to almost black. Coarse hair often grows on it. Mixed nevus has a smooth surface and can be located on any part of the body.
4. Intradermal nevus. It also protrudes above the surface of the skin, but, unlike a complex nevus, it has an uneven, bumpy surface. Almost always located on the head or neck, very rarely on the torso. In most cases, intraepidermal nevus appears between the ages of 10 and 30 years. Over time, it seems to separate from the skin and is located on a thin stalk. Often it then develops into a papillomatous nevus (verrucous nevus). A large number of irregularities, folds and crevices are formed in it, in which dead cells of the upper layer accumulate. Pathogenic organisms can accumulate here, which then lead to infectious processes.
5. Blue nevus has a characteristic color because it is associated with melanin deposits under the skin. Blue nevi are characteristic mainly of Asian nationalities. They rise slightly above the skin, are dense to the touch, their surface is always smooth, and hair never grows on it. The blue nevus is small in size, most often no more than five millimeters.
6. Basal nevus also has the appearance of a mole, but most often it has a normal flesh color. This is a non-pigmented nevus.
7. Nevus of Seton (nevus of Setton, nevus of Sutton, halo nevus) – a special type of dermal nevus, when around the pigment spot there is an area of skin completely devoid of pigment. The origin of such nevi has not yet been fully studied. They are often combined with vitiligo (loss of skin pigments), melanomas. Most often, there is a slight inflammation in the skin in the area of the nevus halo.
8. Nevus Ota. It is located on the face, on the one hand, in the form of “dirty” spots.
9. Nevus Ita resembles nevus of Ota, but it is located under the collarbone, on the chest, in the area of the scapula and neck. Both of these varieties are found mainly among representatives of Asian peoples.
10. Papillomatous nevus (warty nevus) . A papilloma-like nevus often has big sizes, is located on the head or on the back of the neck, but can also be located in other places. It has an uneven surface, like a wart. Hair often grows on it.
11. Becker's nevus (hairy epidermal nevus) – most often occurs in boys and young men aged 10–15 years. First, several small spots, which are light brown or brown in color, and are nearby. Then they merge and form spots with uneven contours up to 20 cm in size. After this, the spots acquire an uneven warty surface and are covered with hair. It is believed that the growth of Becker's nevi is caused by the release of a large amount of male sex hormones - androgens - into the blood.
12. Linear nevus- a neoplasm that appears from birth. It consists of many small nodules, from light to almost black in color, which are located on the skin in the form of a chain. A linear nevus can occupy only a couple of centimeters, or maybe the entire arm or leg. Sometimes hair grows on it.
13. Nevus of the eye– pigmented nevus, which is located on the iris. It is clearly visible in the form of a spot that may have different sizes and shape. Also, an eye nevus may be located on the retina: in this case, it is detected only during an examination by an ophthalmologist.

All skin nevi can be classified by size:

small nevi measuring 0.5 - 1.5 cm;
medium non-water dermal nevi - 1.5 - 10 cm;
large pigmented nevi measure more than 10 cm;
if a nevus is located on an entire area of the body, occupying it almost entirely, then it is called giant.

With time appearance pigmented nevi may change. Their total number on the body also changes:

It is not always possible to detect nevi on the body of a newborn. Only in 4–10% of children infancy moles can be identified. If nevi are large in size from birth, then they are the most dangerous in terms of malignancy (transition to melanoma).
In adolescence (10–15 years), dermal nevi can be found in 90% of individuals.
On average, a person aged 20-25 years can have up to 40 moles on his body.
After 30 years, only 15–20 nevi remain on the skin.
In a person who has reached 80–85 years of age, it is almost impossible to detect nevi on the body.

This dynamic is associated with a change hormonal levels during a person's life.

Complications of pigmented nevi

Almost the only and most dangerous complication nevus is a malignancy. In this case, the pigment spot turns into melanoma - a tumor that, having reached advanced stage, is one of the most dangerous.

Above we looked at many types of nevi. Not all of them are equally dangerous in terms of malignancy. The most dangerous nevi (melanoma-dangerous) are blue nevus, borderline nevus, nevus of Ota.

Risk factors for developing melanoma include:

the appearance of large nevi from birth;
the appearance of nevi in late and old age;
the presence of giant nevi: the larger the size of the pigment spot, the more dangerous it is in terms of degeneration into melanoma;
the presence of a large number (more than 50) non-waterermal nevi on the body;
constant appearance of new moles and nevi;
nevi located in places that are constantly in contact with clothing and experience friction (in the ankle area, on the belt, on the neck);
frequent injury, inflammation of the skin in the area of the nevus.

Signs of the onset of nevus degeneration may include:

rapid growth;
appearance discomfort: pain, itching, tingling, etc.;
rapid change in color of the mole, acquiring a black or blue color;
surface change: appearance of bumpiness, intense hair growth;
a change in the shape of the spot when its contours become less clear;
the spot or mole begins to become constantly wet, or periodic bleeding is observed;
the appearance of strange peeling of the skin/

If such symptoms appear, you should immediately consult a doctor.

Diagnosis of nevus

The doctor who diagnoses nevus faces a number of important tasks:

establish the type of nevus and determine the possibilities of its treatment;
recognize in time the onset of the process of malignancy of the pigment spot;
determine indications for additional diagnostic methods.

The examination of the patient begins classically with a conversation and examination.

During the questioning, the doctor must establish important details:

when did the non-waterermal nevus appear: it is especially important whether it was present from birth or arose with age;
how the formation has behaved over the last time: has it increased in size, changed color, contours, general appearance;
whether diagnosis and treatment were carried out previously, what was the result: for this, the doctor must provide the relevant extracts and certificates.

Direct contact with the patient is very important. No one professional specialist will not undertake to diagnose and treat a nevus based on a photo.

After questioning the patient, an examination follows. The doctor must evaluate the shape, size, location of the nevus, the presence of hair on it and other features. After this it can already be delivered accurate diagnosis and certain therapeutic measures are planned.

If necessary, a doctor will prescribe additional methods diagnostics

Most often, smears from the surface of the nevus are used. Absolute indications To this study is weeping, bleeding, cracks on the surface of the pigment spot. During the smear, material is obtained, which is then examined using a microscope. Usually the finished result can be obtained the next day. In the laboratory, they study the cells that make up the pigment spot - this allows us to determine what nature the nevus has, how much high danger it represents in terms of degeneration into melanoma.

Taking a smear has one drawback: at this time, microtrauma of the surface of the nevus occurs, which, under certain conditions, can provoke malignant growth. Therefore, the study is carried out only in specialized oncology clinics and departments, where it will be possible to immediately remove the pigment spot.

More secure fluorescence microscopy method . In this case, the nevus is also examined under a microscope, but without taking smears, directly on the patient’s body. To do this, a special device is used - a dermatoscope, which illuminates the skin. A small amount of oil is applied to the pigment spot, which will enhance the glow. After this, the device that will be used to conduct the study is placed directly next to the oil stain. Fluorescence microscopy is an accurate, safe and painless procedure. The problem is that not every clinic has dermatoscopes.

Also today, modern computer diagnostics nevi in newborns and adults. Using this technique, an image of the pigment spot is obtained, which can then be saved on a computer. By quickly comparing it with the existing database, the doctor can determine correct diagnosis and prescribe treatment.
Computer diagnostics is an expensive technique, and this complicates its widespread implementation in practice.

Laboratory diagnostics used to establish the process of degeneration of a nevus into melanoma. When a pigment spot becomes malignant, special substances – tumor markers. Their detection allows an accurate diagnosis, since only with melanoma two molecules called TA90 and SU100 are detected in the blood. In other malignant tumors, other tumor markers are detected.

To conduct an analysis for tumor markers, clear indications are required: the doctor must have good reason to suspect the transition of a nevus to melanoma.

In addition, the removal of a dermal nevus itself may become diagnostic procedure. After the pigment spot is removed, the doctor must send it to histological examination. He is examined under a microscope and, if malignant degeneration is detected, the patient is again asked to come to the clinic.

Treatment of nevi

Currently, there are several methods for treating pigmented nevi, such as surgically, so alternative ways. The choice of a specific technique cannot be determined by the wishes of the patient himself.
Indications are determined only by the attending physician, taking into account two factors:
1. Features of the pigment spot itself: type, size, risk of transition to melanoma.
2. Availability of necessary equipment in the hospital. For example, many small clinics, due to the lack of appropriate equipment, only practice excision of nevi with a scalpel.

Surgical method
Removing a pigmented nevus surgically (using a scalpel) is the most common technique, as it does not require special equipment and is reliable. Basically, this tactic is indicated for large nevi. Surgical intervention has three significant disadvantages:

after removal of a nevus, scars and cicatrices often remain;
in accordance with the rules of oncology, the surgeon is forced to remove not only the pigment spot itself, but also the skin that surrounds it, 3–5 cm around;
if the formation is small, then in adults the nevus can be removed under local anesthesia, but in young children it is almost always necessary to use general anesthesia.

Sometimes very large non-waterermal nevi have to be removed in parts. Surgeons extremely rarely resort to stage-by-stage excision of the nevus, because the remaining injured part of the pigment spot can grow rapidly or degenerate into malignant tumor.

Cryodestruction
Cryodestruction is a method that involves treating nevus using freezing. After processing low temperatures the pigment spot dies and turns into a scab (crust), under which a new one grows normal skin. To carry out cryocoagulation, liquid nitrogen and carbonic acid ice are often used (as you know, carbonic acid is a liquid that easily turns into steam, so when making ice from it, the temperature is significantly reduced).

The technique is good compared to surgical intervention, as it does not leave scars and does not require the removal of large areas healthy skin, almost painless.

But with cricoagulation it is not always possible to completely remove the nevus; it is often necessary to conduct a second session after the spot begins to grow again. During the session, healthy skin may be damaged.

Treatment of a nevus with low temperature can only be carried out if it is small in size and located superficially, but not protruding much above the skin.

Electrocoagulation
This is a technique that is the opposite of cryocoagulation. Excision of the nevus is carried out under the influence high temperature. This method has several advantages over surgery:

during excision, an electric knife or an electrocoagulator simultaneously cauterizes the wound on the skin, so there is virtually no bleeding;
there is no need to remove large areas of healthy skin around the nevus.

At the same time, electrocoagulation, like cryodestruction, does not make it possible to remove pigmented nevus big size. The procedure is painful and therefore requires local anesthesia, and in children only general anesthesia.

Laser therapy
Laser removal of nevi is a treatment method that is widely used in modern beauty salons. It is great for removing small moles on the face, neck and other parts of the body.

Laser radiation is different in that it can penetrate the skin at greater depth within a precisely specified area. In this case, scars, burns, cicatrices and other complications are not formed. The procedure is painless.

However, removing large nevi using a laser has some difficulties. Firstly, this is not always technically possible. If part of the pigment spot is left, it will continue to grow. Secondly, often after laser therapy there remains at the site of the removed nevus big spot, devoid of pigment and having a white color.

Radiosurgical methods
IN last years Radiosurgery is increasingly used in world medicine. The essence of these methods is that special device, - a radioknife (surgitron) generates a beam of radioactive radiation, which is concentrated only in the area of the pathological focus, without harming healthy surrounding tissues. In this way, almost any benign and malignant tumors, including pigmented nevi, can be removed.

Despite the fact that radiosurgical techniques are relatively young, today they are actively used in Russia, and necessary equipment Available not only in specialized clinics, but also in beauty salons.

In this case, radioactive radiation acts on the nevus in three directions:
1. Cuts through the skin, removing pigment spots.
2. At the site of radiation, a small radiation burn, which is not enough to lead to the formation of scars and scars, but is enough to stop bleeding - thus, radiosurgery is a bloodless method.
3. Moderate doses of radiation also have a disinfecting effect.

Radiosurgery has one main contraindication, the same as other alternatives to surgical excision: using this technique it will not be possible to remove a large nevus.

Some special indications
If there is a suspicion of malignant degeneration of the nevus, then, as a rule, only surgical excision is used. In this case, all surrounding tissue is removed to prevent further growth of the tumor.

Some types of nevi can only be treated with surgery.

Prevention of malignancy of nevi

Above we have already listed some risk factors for the development of melanoma from a nevus. This dark spots large size, congenital and multiple moles, a sharp increase in their number.

There are no specific ways to prevent pigmented nevus from turning into melanoma. However, people at risk should follow some rules:
1. Must be avoided long stay outside from 11 a.m. to 5 p.m. – this is the time when the skin is exposed to the most intense solar radiation.
2. The areas where large nevi are located should not be exposed to heavy tanning. It is worth remembering that in summer, even in cloudy weather, human skin can absorb up to 85% of ultraviolet radiation.
3. Some believe that you can protect moles from ultraviolet radiation with special creams and lotions. In fact, these products only protect against tanning, but do not reduce the risk of developing melanoma.
4. Staying in a solarium has a similar effect on the skin. Especially not recommended this procedure persons under 28 years of age who have multiple or large age spots.
5. If you notice any changes in existing moles, or the appearance of a large number of new moles, you should immediately consult a doctor for examination and control.

Currently, there is an increase in the frequency of transformation of non-waterermal nevi into melanomas, especially in developed countries with unfavorable conditions. environmental situation. In Russia, melanomas are diagnosed in 4 people out of 100,000.

Before use, you should consult a specialist.

– benign skin lesions related to malformations of melanin-forming elements (epidermal melanocytes), which synthesize the pigment melanin, which protects the body from excess UV radiation.

Melanocytic nevi found in ¾ of the population with light skin color, in any area. They can be congenital, but more often occur after birth. Their number and size increase until the age of 16-18, and then decrease. Some of them have malignant potential; pigmented formations that continue to grow after 18 years, as well as rapidly growing nevi in children, should be especially alarming.

In accordance with the classification by J. Bhawan (1979), according to the stages of development, melanocytic nevi of epidermal origin are divided into three main types:

Intraepidermal (borderline) nevus
Complex nevus
Intradermal nevus

Stages of development

Melanocytic nevi of epidermal origin appear in childhood and reach their maximum number in adolescence. The appearance of new nevi in adults is possible, but not so common. In their development, they always go through several stages, which culminate in involution and fibrosis.

With age, nevus cells usually gradually penetrate into the papillary dermis and the nevus becomes complex or intradermal.

Intradermal nevus is last stage development of melanocytic nevus. Immersion into the dermis is complete. Here the nevus continues to grow or enters a dormant stage. Over time, it undergoes fibrosis. As nevus cells sink into the dermis, they lose the ability to synthesize melanin, and the noncellular nevus loses pigmentation. The fewer nests of nevus cells left in the epidermis, the lighter the color of the nevus.

Borderline nevus

In children, borderline nevi are most often observed, in which nests of nevus cells are located above the basement membrane, at the border of the epidermis and dermis.

Clinical picture manifests itself as a spot, less often a papule, round or oval shape, with smooth; surface, uniform pigmentation from yellowish to Brown. The diameter of the formations is from 1-2 mm, on average up to 1 cm, but can reach 4-5 cm. Elements of a borderline nevus are randomly scattered in the body area, upper limbs, faces, lower limbs, sometimes localized on the palms and soles.

Dermoscopically The border nevus is represented by a typical brown pigment network. The partitions of the mesh are uniform, the cells within the mesh differ slightly. The network is less pronounced along the periphery of the formation. Black spots or brown granules may be present, usually concentrated in the center. There are also zones of homogeneous pigmentation. In general, during dermatoscopy, borderline nevus is distinguished by uniform coloring and orderly arrangement of elements of the dermoscopic picture.

Histologically A border nevus is characterized by clearly demarcated nests of melanocytes in the lower layers of the epidermis. In the upper layers of the dermis, an increased number of melanophages and minimal subepidermal infiltrate are detected.

A borderline nevus can turn into a complex nevus, which most often occurs during puberty.

Rice. 1. Borderline nevus.
a) Clinical picture;
b) Dermatoscopy - a typical pigment network with uniform partitions of brown color;
c) Histology - nests of melanocytes are detected in the lower layers of the epidermis.

Complex nevus.

Transitional type of development of melanocytic nevus.

Clinical picture looks like a pigmented papule, sometimes with papillomatosis, rarely reaching 1 cm in diameter.

Dermatoscopic picture represented by a uniform pigment network, uniform granules and dots. There are also homogeneous areas, localized mainly in the center. Papillomatous nevi may also contain horny plugs and milia-like cysts. Comma-shaped vessels are often visible.

At histological In the study, nevus cells are located in nests, cords and clusters in the basal layer of the epidermis, the border zone and in the dermis.

Rice. 2. Complex nevus.
a) Clinical picture;
b) Dermoscopically - uniform granules and points are determined;
c) Histologically, nevus cells are located in the basal layer of the epidermis, the border zone and in the dermis.

Intradermal nevus.

Clinical picture looks like a dome-shaped or papillomatous formation with a pronounced stalk, less often it can be in the form of a blackberry node on a broad base. The surface may be covered with hair. The diameter of the nevus is about 1 cm. The color is from light brown to black, in some cases it can be reddish or whitish, sometimes translucent.

Dermatoscopic picture intradermal nevus is represented mainly by the “cobblestone pavement” phenomenon. In addition, during dermatoscopy of a dermal nevus, black dots, faintly colored granules and a more or less pronounced pigment network, comedon-like openings and vessels resembling commas can be detected.

At histological In the study, cords and nests of nevus cells are located in the dermis. Nests of nevus cells are separated from the epidermis by a narrow layer connective tissue. The nests consist predominantly of oval and cubic cells, with rounded hyperchromatic nuclei. In the upper layer of the dermis, nevus cells are larger and contain a moderate amount of pigment. As nevus cells mature, they remain round but become smaller and non-pigmented. Spreading deep into the dermis, they acquire a spindle-shaped shape and form narrow columns and cords.

Rice. 3. Intradermal nevus.
a) Clinical picture;
b) Dermatoscopically - the phenomenon of “cobblestones”, vessels in the form of a comma;
c) Histologically, nests of nevus cells are located in the dermis.

A benign brown pigment formation located simultaneously in the epidermal layer of the skin and the dermis. A complex nevus looks like a round papule or wart with a diameter of up to 1 cm, rising above the skin level. Its diagnosis includes examination, dermatoscopy and siascopy, and, if necessary, ultrasound. Histology of a complex pigmented nevus is carried out after its removal. Given the likelihood of nevus transformation into melanoma, patients need to be monitored by a dermatologist. The safest and optimal methods for removing a complex pigmented nevus are the radio wave method and surgical excision.

General information

A complex pigmented nevus looks like a papule or dome-shaped node, round shape. Its surface is often smooth, and the growth of bristly hair is noted on it. There are complex nevi with a keratinizing or warty surface. In most cases, the nevus is located on the face or scalp, but can have any location. A complex nevus rarely reaches a significant size, usually its diameter does not exceed 1 cm.

Diagnosis of complex pigmented nevus

A complex pigmented nevus is diagnosed by a dermatologist based on examination, dermatoscopy and siascopy of the pigment formation. To determine the extent of nevus growth into the dermis, ultrasound of the skin formation can be used. Suspicion of malignant degeneration of a nevus or melanoma is an indication for urgent consultation with a dermato-oncologist.

Carrying out a biopsy of a complex nevus is dangerous due to its injury, which can lead to malignant degeneration to melanoma. For this reason, histological examination of nevus tissue is most often carried out after its complete removal. It reveals the characteristic arrangement of nests of nevus cells in both the epidermis and dermis.

Differential diagnosis of a complex pigmented nevus is carried out primarily with melanoma and other types of pigmented nevi: blue nevus, borderline pigmented nevus, Setton's nevus, Dubreuil's melanosis, as well as applicable in the case of a complex nevus, if it involves using a laser as a scalpel and allows conduct a subsequent histological study of the removed formation. It is most advisable to use the radio wave method or surgical excision of a complex nevus, since they make it possible to completely remove nevus cells, which has great importance in terms of preventing melanoma.

Every person with light skin color has moles or nevi on their body. They can be both congenital and acquired. A melanocytic nevus is a small spot on the skin characterized by darker pigmentation.

There are several types of moles:

intradermal;
melanocytic;
warty or papillomatous;
congenital.

Melanocytic nevi are any pigmented moles on the body.

An intradermal pigmented nevus is a spot formed due to a disturbance in the production or distribution of melanin. Such spots, as a rule, appear in early childhood and remain with a person for life. The following symptoms are characteristic of intradermal or intradermal melanocytic nevus:

color uniformity throughout life;
absence of unpleasant sensations in the area of the mole;
clearly defined contour;
absence of inflammatory processes in cells.

As a rule, such nevi are safe and do not transform into melanoma.

Papillomatous melanocytic nevus is one of the types of intradermal nevi. Such spots are characterized by the presence of a stalk and a lighter shade. Outwardly, they are easily confused with papilloma due to the fact that the mole looks like a growth. Typically, papillomatous intradermal melanocytic nevi are light pink in color and soft in texture. Such growths do not have a clearly defined contour and do not pose a danger, but they are often injured.

Congenital melanocytic nevi are rare. The development of such a formation on the skin begins in the prenatal period, so the child is born with a mole. Distinctive feature The reason for such spots is that they increase in size as the child grows. Small specks do not pose a danger, unlike large ones. If the surface of the mole is heterogeneous, any changes should be carefully monitored and observed by a dermatologist.

There is also a complex nevus of the skin, which is dark spot convex shape. Such benign neoplasms may develop into melanoma and therefore require careful monitoring. Doctors often suggest removing such spots.

Why do moles appear?

An intradermal melanocytic nevus is a cluster of specially pigmented cells. Factors leading to the appearance of moles on the skin:

Many people have probably noticed how new spots appear on the skin after severe sunburn. Exposure to sunlight can lead to disruption of pigment production and the formation of spots of any size.

IN childhood new moles often appear after a course of phototherapy. There is also an increase in the number of spots with atopic dermatitis in newborns.

Disturbances in skin pigmentation and the appearance of new age spots and moles are often observed after burns. Household, chemical and sunburn, accompanied by the formation of large blisters on the skin, are one of the common causes of acquired melanocytic nevi.

Some inflammatory processes and skin infections can also cause the development of melanocytic spots. The appearance of moles after treatment for lichen is often noted.

The formation of new moles is observed in women during periods hormonal changes body. So, spots can appear on the body during puberty, pregnancy and at the onset of menopause.

The appearance of congenital melanocytic nevus is due to the peculiarities of intrauterine development of the fetus.

Which nevi are dangerous?

In most cases, melanocytic moles do not pose a health risk. Their flat shape allows them to avoid injury and damage, so the risk of cells degenerating into a malignant tumor is minimal.

Papillomatous intradermal nevus and complex convex spots require observation. Development risk negative consequences for damage to such spots is quite high, so the patient is recommended to be checked annually by a dermatologist.

The following symptoms are reasons to visit a doctor:

itching of the skin around the spot;
inflammation of moles;
increase in size or change in color of the spot;
sudden bleeding;
peeling of the skin.

If the nevus is located in areas of contact with clothing or in skin folds, you should consult your doctor about the possibility of removing it.

Mole injuries

Often moles are damaged in everyday life. This often happens with spots located in depilated areas, skin folds or on the face in men. Accidentally cutting off a nevus while shaving is one of the most common causes of damage to these benign formations.

Raised spots can be accidentally damaged in everyday life, for example, while taking a shower. Any injury can cause bleeding.

Having noticed that after damage to a mole there is bleeding, it is important to carry out timely antiseptic treatment and stop the bleeding. To do this, the wound is treated with hydrogen peroxide, and then pressed tightly with a swab made of a sterile bandage. It should be remembered that under no circumstances should damaged nevi be allowed to become infected in order to avoid the development of negative consequences.

Removal and diagnosis of nevi

Diagnosis of nevi is carried out by a dermatologist and oncologist. A dermatologist carefully studies the features of benign formations using special equipment. If you suspect that the process of cell degeneration has begun, the doctor will recommend consulting with an oncologist.

It should be remembered that tissue scraping from moles is not carried out, as this leads to damage to the moles and is dangerous to health.

Histological analysis is carried out only after removal of the mole. The following methods are used for removal:

surgical excision;
radio knife;
laser removal;
cryodestruction.

All these methods are absolutely painless. Excision of a mole with a scalpel is carried out under local anesthesia. If the mole is located on the face, it is recommended to prefer radio wave or laser method removals that do not leave scars, unlike cryodestruction.

It is imperative to remove melanocytic stains that are subject to friction on clothing or are often damaged in everyday life.

Prevention measures

Despite the fact that transformation of melanocytic nevus cells is quite rare, it is important to avoid factors that injure this formation. To such negative impacts include intense tanning, rubbing with clothing and accidental damage.

If nevi are located on open areas skin, it is important to use sunscreen during periods of strong solar activity.

Protecting the spots with a patch will help prevent damage to skin growths. It is important to remember that if this benign education causes discomfort on the skin, you should definitely consult a doctor about the possibility of removing it.

Almost every inhabitant of the Earth who does not have black skin has at least one mole, which in medicine is called nothing more than a melanocytic nevus. The word “nevus,” somewhat unusual for the Russian language, was borrowed from Latin and means the same mole or birthmark. In the process of life for unknown reasons new moles appear where there used to be clean skin, and the old ones disappear somewhere. This scares some people, and causes inconvenience to others, especially when dark spots begin to “decorate” the forehead, nose, and cheeks. Let's try to figure out what moles, or, in scientific terms, nevi, are, what they are, where they come from, and whether it is possible to somehow influence their appearance.

What is a nevus

In the skin of humans and animals there are special cells - melanocytes, which produce a dark pigment - melanin. In animals, it affects the color and determines the color of the eyes. In humans, it is melanin that is responsible for the intensity of tanning, that is, it protects against ultraviolet and other rays harmful to the body. When the pigment is evenly distributed throughout the skin cells, it has a uniform color and tone. If suddenly - for reasons still unknown to science - an excessive amount of it accumulates in individual cells, such areas begin to stand out against the general background, that is, a birthmark or pigmented nevus appears. Melanocytic nevus is the same. Another synonym for the same concept is melanoform or noncellular nevus. The color of these formations varies from black to light brown, sometimes purple. If the birthmark is red (wine) in color, it is called a flaming nevus and is formed due to large cluster not pigment, but capillaries located too close to the surface of the skin. For example: Gorbachev has a flaming nevus on the head and part of the forehead, last president Soviet Union.

In some people, the melanocytic nevus may be flush with the skin, while in others it may protrude slightly above its surface. The photo above shows a slightly protruding pigmented nevus. In infants, such marks are almost never observed, although scientists tend to believe that they are simply too small to be noticeable. They begin to appear more clearly around the age of 9-10 years. In most cases, simple pigmented nevi behave peacefully and do not cause any problems other than cosmetic defects.

Types of birthmarks

Hairy (one or more hairs grow from a mole, usually dark in color, regardless of whether the person is blond or brunette).

Clark, Spitz,

Let's take a closer look at some of the types.

What is papillomatous intradermal melanocytic pigmented nevus?

This long and somewhat difficult to understand definition contains several concepts at once. Thus, it was already noted above that the terms “melanocytic” and “pigment” mean the accumulation of melanin pigment in the melanocytes that produce it. essentially means the location of accumulations of melanocytes in the deeper layers of the skin and externally represents a tubercle protruding above its surface. Its synonym in medicine is the expression “intradermal melanocytic nevus”. If it has and is also located on a stalk, there is a great resemblance to papilloma. Hence the name - papillomatous nevus. Such formations appear mainly on the head ( hairy part), neck, face, but can also be observed on any other part of the body. Their color, in addition to flesh-colored, can be brown, brown, black, and their finely lumpy structure vaguely resembles cauliflower. In medicine you can find other names for it, for example, linear, hyperkeratotic. There are 2 forms of them - organic, when papillomatous moles are observed sporadically, and disseminated, when there are many such warty tubercles. They are often located where large blood vessels and nerve vessels. If a person has such a pattern, this may indicate diseases of the central nervous system, in particular epilepsy. Although papillomatous intradermal melanocytic nevus of the skin, appearing at birth, constantly grows little by little, it is classified as a benign melanoma-free type of pigmented formations. Despite this, it certainly needs to be shown to a specialist dermatologist to find out whether it is a nevus, papilloma or melanoma. It is especially important to consult a doctor if a papillomatous mole suddenly begins to hurt, itch, or changes color. When establishing a diagnosis, the doctor conducts a visual examination and, if necessary, performs siascopy, ultrasound, and biopsy.

Complex melanocytic nevus

This definition is used when a mole, having originated in the epidermis, grows into the dermis. Outwardly, it looks a little like a wart, not exceeding 1 cm in diameter. Like other types of nevi, the complex one is considered benign, however, according to medical statistics, in more than 50% of cases it can develop into melanoma. Therefore, it is classified as a melanoma-hazardous formation. In its structure, a complex nevus can be smooth, lumpy, hairy, warty, and most often dark in color - from brown to black.

Atypical nevus

It is believed that approximately one in ten people have an atypical or dysplastic melanocytic nevus on the skin. The photo above shows what it might look like. These birthmarks received this name due to their unclear, seemingly blurred boundaries, asymmetry, size (as a rule, they exceed 6 mm), and dissimilarity from other birthmarks. Atypical nevi can be very different in color - from light beige or pink to dark brown. In medicine, there is a synonym for this pigmented formation - Clark's nevus. If you find such a strange birthmark, you should definitely consult a doctor to make sure there is no melanoma. Doctors believe that atypical nevi themselves do not pose a health hazard, but people who have them are at risk for skin cancer, and not necessarily at the site of the pigment spot. During life, atypical nevi, like any other, can disappear on their own, but this is not a reason to exclude a person from the risk group.

Recurrent nevus

This is the name given to pigment spots that appear at the site where a mole was removed. A recurrent nevus usually means that the mole tissue was not completely removed and a repeat operation is required.

Spitz nevus

This is another pigment formation, due to the presence of which people are at risk for melanoma. Such birthmarks appear on the skin more often in children under 10 years of age, but adults are also not immune from them. A distinctive feature of Spitz nevus is its fast growth. So, suddenly appearing on the skin, in just a few months it can increase in diameter from a couple of millimeters to a centimeter or more. Another unpleasant feature is that it can metastasize to adjacent areas of the skin and lymph nodes. But, despite this, in most cases, Spitz nevi are considered benign and can easily be treated in a timely manner.

Nevus of Setton

Sometimes birthmarks with a white border around the edge appear on the body. They go by two names - melanocytic nevus of Setton and halo nevus. Some people have only a few such formations, while others may have many of them, mostly on the back. The white border, scientists believe, is caused by the cells in it being destroyed by cells immune system. Over the years, Setton's nevi may become completely discolored or disappear completely, leaving behind a souvenir bright spot. In the vast majority of cases, such bordered moles do not pose a danger. But scientists have found that their presence, especially in large quantities, may be due to the presence of diseases in their owner such as vitiligo and thyroiditis, or melanoma, which has not yet manifested itself.

Becker's nevus

This birthmark in its size resembles a giant melanocytic nevus. In about a quarter of cases, such pigmentation occurs in the fetus while still in the womb. Distinctive feature Becker's nevi are:

Hair growth on them;

Pimples appearing on them;

An increase in size up to a certain point, then a cessation of growth and some lightening of the color.

Most often, such birthmarks remain with a person for life. They do not pose any danger, but their owners should still be seen by a dermatologist from time to time.

How dangerous are birthmarks?

Some people believe that moles can eventually develop into melanoma or other types of skin cancer. However, this is wrong. In the vast majority of cases, any birthmark (or melanocytic nevus) does not threaten anything. You need to worry and immediately rush to the doctor (dermatologist, oncologist) if suddenly the following changes begin to occur with the mole:

Its color has changed, no matter in which direction;

It has become asymmetrical (for example, convex on one side);

The color or structure of the rim of the birthmark has changed;

The mole began to hurt, itch, and bleed;

The size of the birthmark has increased sharply.

In all cases, if a new mole differs from existing ones, or an old one suddenly becomes somehow unusual, you need to consult a doctor as soon as possible.

What to do with moles?

If the nevi do not bother you in any way, and if they are located on safe areas of the skin, you just need to watch them. If they are located where they can often be injured (on the palms, on the feet, on the neck, on the head, on the waist) or on the face, which causes cosmetic defects, it is recommended to remove them. Such operations should be entrusted only to doctors - a surgeon, a dermatologist. Epidermal nevi are recommended to be removed only surgery. It is performed under local anesthesia and is therefore painless. Papillomatous melanocytic nevus of the skin, especially those located on the stalk, is sometimes more appropriate to remove with liquid nitrogen. In recent years, it has also been successfully used laser treatment moles and their excision with a radio knife.

After surgery, the doctor, as a rule, sends the removed fragments for histological examination to be completely sure that there is no cancer.

It is completely unacceptable to remove nevi on your own, traditional methods. Especially often, people try to get rid of papillomatous nevi on the legs by tying them with thread. This leads to blocking the blood supply to the mole, and it may actually fall off. But in most cases, this method of “treatment” provokes the development of changes in the cells of the epidermis or dermis and leads to disastrous consequences.