Mixed complex nevi: what every person should know about moles. Melanocytic nevus: causes, symptoms, treatment

It has been statistically revealed that nevus is registered on the body of every third person Caucasian. The number of these skin tumors in each person can vary from a few to hundreds. In childhood, nevi may be small in size, but over time, under the influence of certain factors (sun, pregnancy), they may increase in size and even become cancerous.

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What is a nevus?

A nevus (nevoid tumor), more simply called, is a collection of nevus cells localized in various skin areas and formed as a result of a developmental defect.

This type of cell arises in utero from the neural crest, from which many organs and tissues are formed. Due to the incomplete transformation of nevoid cells into melanocytes (pigment structures of the skin), they do not penetrate into the deep layers of the skin, but are retained in the dermis (the layer of skin under the epidermis).

Are there malignant nevi?

Along the path of its development, the nevus goes through several stages: first it is intraepithelial, then borderline and intradermal (after 30 years). IN old age maybe it's reverse development and replacement with connective tissue. So, they distinguish:

Border view:

It appears before the age of 20 and is localized almost everywhere. Visually, it is a uniformly colored rounded formation of a brown tint, up to 1 cm in diameter, with a smooth surface and clear outlines.

Mixed:

It is a transitional stage between borderline and intradermal. It is characterized by a spherical shape, dense structure, dark brown or black color, up to 1 cm in diameter.

Intradermal:

Occurs after 45 years in single or multiple formations. It is distinguished by a warty shape (outwardly reminiscent of a raspberry), from 0.2 to 3 cm in diameter, dark brown in color, but may be uncolored.

Congenital:

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How to recognize malignant transformation?

In order to detect an oncological process in a timely manner, you need to pay attention to the area with formation Special attention. Malignancy can be suspected based on the following signs:

• the appearance of blurred boundaries;
• change in the vascular pattern around the mole;
• violation of the integrity of the surface in the form of abrasions or cracks;
• rapid growth;
• discomfort, burning, itching in the area of ​​the tumor;
• surrounding inflammation around the formation;
• change in shade;
• the appearance of discharge from a mole.

In addition, you should pay attention to nearby lymph nodes, as they can not only become inflamed, but also be affected by metastases. They may become hard, immobile, enlarged, and adherent to adjacent tissues and structures.

Malignant degeneration of nevus into melanoma

When the formation is localized in open areas for aesthetic reasons, atraumatic suture material is used, which will ensure complete healing of the postoperative wound without a visible defect.

According to the standards of oncological surgery for melanoma with the aim of excision of all cancer cells 5 mm of healthy tissue should be captured in the removed conglomerate. In addition, if the lymph nodes are affected, the issue of their removal is considered.

As for the fight against non-dangerous moles on the face and neck, you can use cauterizing solutions, laser or electrocoagulation.

Regardless of the type of formation and the risk of its malignancy, it is advisable to follow preventive tips:

1. avoid burning sun rays, solarium;
2. promptly remove suspicious moles if they are located in traumatic areas;
3. review regularly nevus for changes in color or shape.

Pigmented nevus is a skin disease. This condition is benign and occurs quite often. In the literature you can see the names “noncellular” and “melanocytic” - these are synonyms, we are talking about the same process.

Noncellular nevus – any congenital disease associated with the proliferation of nevocytes. These are skin cells in which the pigment melanin accumulates. They are very similar to melanocytes, but do not have processes and are less susceptible to the regulatory influences of hormones and other active substances. Nevus cells include round nuclei, their ability to divide is low. Externally, nevi may look like this:

• flat spots that blend into the skin;
• Maculae – spots raised above the surface of the skin;
• dome-shaped tumors or papillomas resembling a wart.

Many researchers believe that pigment formations do not arise during life, but only appear under the influence of certain factors, primarily sunlight. Infants have almost no moles, but in teenagers they are very common. U young man up to 40 can be found on the skin birthmarks. With age they fade, disappear, and by old age they are practically absent.

These formations are found in most people. The number of their types is very large. According to WHO recommendations, there are:

• border;
• difficult;
• intradermal;
• spindle cell (epithelioid);
• nevus formed by balloon-shaped cells;
• halonevus;
• giant pigmented nevus;
• involutional (fibrous nasal papule);
• blue and checkered blue.

Types of pigmented nevus formations

Let us dwell in more detail on the features of the most common or most dangerous types.

Border

Borderline pigmented nevus, synonymous with functional nevus - First stage development skin lesions. It is localized in the very top layer skin- epidermis. The formation is congenital or acquired. It often develops in childhood and adolescence, localizing on the palms or soles. At microscopic analysis visible clusters, called nests, of nevocytes in the lower epidermal layer at the border with the dermis, hence the name. This type is melanoma-dangerous because it can often degenerate into malignant tumor.

It is a flat pigment formation. For a long time, pigmented nevi are small in size - up to 3 mm, which gives a person the impression that he has had these spots since birth. In some cases, borderline nevi begin to grow rapidly - 1 mm per year, growing in a few years to a size of 5-6 mm. With such a significant increase in the spot, it is necessary to show such a growing mole to an oncologist. It can transform into a dysplastic nevus, a precursor to skin cancer.

Intradermal

Most common form age spots– intradermal pigmented nevus. It is otherwise called a “resting”, inactive, mole or birthmark. It is characterized by a variety of shapes and colors. Mole is the most common benign education. It looks like a flat plaque up to half a centimeter in diameter, of any shade Brown, evenly colored, with a dense texture, rounded shape and clearly visible boundaries. The outer layer of such a formation can be convex, in the form of a wart or a hemisphere. In this case, a papillomatous melanocytic pigmented nevus of the skin is formed.

Nevocytes are located deep in the dermis, its middle and lower layers, forming clusters there. Cells have different shapes and quite large in size. If they have small nuclei arranged in the form of rosettes, this confirms the benign nature of the formation. Intradermal pigmented nevus may be visible at birth or appear at an early age.

Difficult

Such a nevus is localized both in the upper layer of the skin - the epidermis, and in the middle - the dermis. It is determined on the surface of the skin in the form of a protruding plaque or papilloma (wart). Nest accumulations of nevocytes are located at the point of contact of the upper and middle layers of the skin. If they begin to spread deeper into the thickness of the dermis, they say that the nevus is maturing. This is a benign process.

Neocytes lying in the upper layer of the skin are less mature, which increases their potential for malignancy. They are quite large, have a cubic shape, synthesize melanin and form clusters in the form of nests. Mature nevocytes lie in the deep layers; they are smaller and accumulate less melanin, so their cytoplasm is lighter. They grow with the formation of cords.

The most mature nevocytes are located in the middle of the neoplasm; they have a spindle-shaped, elongated shape. These cells form bundles that resemble peripheral nerve tissue.

Complex nevi in ​​the form of papillomas or polyps usually contain many vessels.

Pigmented nevi

Other types

Balloon nevus

Rarely encountered formation. It is characterized by huge cells with light cytoplasm compared to ordinary nevocytes. Under a microscope, they resemble inflated containers, or balloons, hence the name. They can be located intradermally, but sometimes this type is complex - the cells lie in two layers of skin.

Halonevus or Setton's nevus

It appears as a hyperpigmented (dark) area of ​​skin surrounded by a lighter (depigmented) surface. Sometimes he disappears without any notice external influence, after which a discolored spot remains on the skin. This formation is often localized on the back of people young, children. Clusters of nevocytes lie in two layers of the skin. A feature of this condition is the accumulation in the area of ​​nests of immunocompetent cells - lymphocytes and macrophages, as if infiltrating the nevus focus with the formation inflammatory infiltrate. Immune cells gradually destroy nevocytes - this explains the zone of depigmentation around the spot. Over time, nevocytes disappear under the influence of immune cells. This type of pigment formation is not melanoma-hazardous.

Often refers to a giant form. A giant nevus is located on any part of the body, including the scalp. Its cells grow in the thickness of the dermis and form extensive clusters in it. Such education has high risk transformation into a malignant tumor (from 2 to 10%).

Spindle cell or epithelioid nevus

It is observed mainly on the face. Its other names are juvenile melanoma or Spitz nevus. The formation looks like one flat or hemispherical nodule. Sometimes it has a surface covered with papillae - papillomatosis. The color of the formation ranges from pink to dull yellow. Around the nodule, dilated small vessels are often visible -. Transformation into atypical form occurs rarely, although upon histological analysis (under a microscope) such a formation is similar to a malignant skin tumor at the beginning of its formation. Nevocytes occur in the form of rounded and elongated clusters. The cytoplasm of these cells is light because they usually do not contain melanin. In the underlying part of the formation, deep in the dermal layer, the cells become spindle-like. There are many around them blood vessels, from which red blood cells sweat, inflammatory infiltration.

Blue nevus

Otherwise called the Mongolian spot. The cells lie deep in the middle layer of the skin - the dermis. They have no connection with the epidermis. The deep location of nevocytes causes the external effect - the blue color of the spot. The lesion is located on the face, torso, skin of the lower back and hands in the form of single spots of a fairly regular pattern. round shape blue or gray having a well-defined boundary. Such pigmented nevi are invisible above the surface of the skin or rise slightly above it. They become malignant in in rare cases. At microscopic examination in the deep layers of the skin, including subcutaneous fatty tissue, thin branching cells are found - special kind nevocytes, which contain a lot of the coloring substance - melanin.

Cellular blue nevus is formed by large spindle-shaped cells and an infiltrate consisting of immunocompetent cells - lymphocytes. There is little melanin in it.

Halonevus or Setton's nevus;
Blue nevus

Dysplastic nevi

Any pigmented formation can degenerate into a tumor with signs of malignancy (uncontrolled growth, possibility of metastasis) -. The risk of such transformation is especially high if there is a dysplastic pigmented nevus.

The link between hyperpigmentation and skin cancer has been discovered for almost 200 years, but it wasn't until 1978 that the true precursor to melanoma was found. Such formations (dysplastic nevi) are otherwise called VK moles (after the letters with which the surnames of the very first families studied then began). They are larger than normal birthmarks, their diameter can exceed 12 mm. Outwardly, they look like flat plaques; their surface may be uneven and their shape may be irregular. They rise slightly above the surface of the skin and are unevenly colored in brown shades. Sometimes such structures do not contain melanin.

On histological examination, the formation looks like a complex or mixed pigmented nevus, but there are signs of infiltrative growth, that is, penetration into the surrounding layers of the skin. The shape of the cells also changes: they become angular, with uneven contours, with brightly colored (hyperchrome) nuclei. The condition that allows melanoma to be excluded is the absence of penetrating (infiltrative) growth towards the upper layer of the skin - the epidermis.

VK moles can appear at any age and on any part of the body. Sometimes their number exceeds several dozen. If there are already such cases in the family, the probability of such a nevus appearing over the age of 59 years exceeds 50%. In this case, the disease is transmitted in an autosomal dominant manner. In this case, they talk about FAMMM syndrome (Family atypical multiple mole melanoma syndrome). This is the main factor in the development of skin cancer.

If a dysplastic nevus occurs in isolation, without hereditary predisposition, then it has a benign course.

Juvenile melanoma;
Dysplastic nevus

Pigmented nevus of the conjunctiva

This formation is practically not dangerous. It can be located on the conjunctiva (mucous membrane) and is then clearly visible. Also, a pigmented nevus of the eye may lie on choroid eyeball and can only be detected during a fundus examination by an ophthalmologist. This spot is formed by accumulations of melanocytes and looks like an ordinary mole.

Eye nevi can be stationary (not changing) or progressive (growing). If the lesion on the choroid grows, over time it can cause a narrowing of the visual fields, reduce its acuity and cause other unpleasant symptoms. Therefore, it is removed using micro surgical operation or laser therapy.

Treatment of nevi

Treatment of pigmented nevus is carried out in cases where the formation is melanoma-dangerous, grows rapidly or is located in an area where it is constantly injured (for example, on the chin, temples, neck, lower back). If a person has age spots, he should regularly visit a dermatologist to have them examined and monitored.

Removal of a pigmented nevus is performed using surgery or minimally invasive intervention.

Removal of pigmented nevus surgically carried out when there is a risk of malignancy of the formation. Excision of the spot using a scalpel is carried out within healthy tissue, after which a scar may remain.

Minimally invasive methods are more often used on open areas of the skin, when the removal of age spots is primarily for aesthetic purposes. Applied, removal using the so-called.

Prevention of malignancy

The most likely malignant degeneration of large, unevenly colored, numerous formations. You should consult a doctor if a mole begins to grow, its surface or shape changes, redness appears around it, or skin itching, bleeding, peeling, sudden hair growth on the surface.

To prevent melanoma (skin cancer), you should follow simple rules:

• Avoid skin exposure to direct sunlight from 11 a.m. to 4 p.m.;
• refuse to visit the solarium;
• prefer light clothes with long sleeves, wear wide-brimmed hats in summer.

Using sunscreen does not reduce the risk of developing melanoma.

Pigmented skin nevus is a benign formation that is located simultaneously in the epidermal layer of the skin and the dermis. A pigmented nevus looks like a papule or wart that rises approximately 1 cm above the skin level.

This type of nevus belongs to the main types of melanocytic nevi of epidermal origin. The nevus begins its growth in the epidermis and ends in the dermis, which distinguishes pigmented nevus of the skin from moles. Therefore, a pigmented nevus is called a complex nevus. About clinical manifestations, diagnosis and treatment of pigmented nevus, read on.

The main clinical manifestations of pigmented nevus of the skin

Complex pigmented nevus of the skin combines the features of intraepidermal and intradermal nevus. The intense brown coloration of the nevus is due to the epidermal component. According to many researchers, up to 80% of nevi degenerate into melanoma, despite their initially benign nature. Therefore, in dermatology, pigmented nevus of the skin is classified as melanoma-dangerous.

The intradermal component of the nevus contributes to its elevation above the surface of the skin. That's why it resembles a wart.

Pigmented nevus of the skin looks like a node or papule with a smooth surface. Sometimes they meet complex nevi with a warty or keratinized surface. Most often, pigmented nevus of the skin is localized on the scalp, but may have a different location. A nevus can reach a size of up to 1 centimeter in diameter.

Establishing diagnosis. Methods for diagnosing pigmented nevus of the skin

The diagnosis of “complex pigmented nevus of the skin” is made on the basis of an examination by a dermatologist, skiascopy and dermatoscopy. To determine the extent of nevus growth into the dermis, ultrasound of the skin formation is used. If melanoma is suspected, the patient should be referred for consultation to a dermato-oncologist.

A biopsy of a pigmented nevus of the skin is dangerous due to its possible transformation, which can provoke malignant degeneration into melanoma. Therefore, histological examination of nevus tissue is carried out after its complete removal.

Differential diagnosis of pigmented nevus of the skin is carried out with the following pathologies:

• blue nevus;
• warts;
• papilloma;
• Setton's nevus;
• Dubreuil's melanosis;
• borderline pigmented nevus;
• dermatofibroma.

Treatment tactics for pigmented nevus of the skin

If there is a pigmented nevus of the skin, the patient should be under the supervision of a dermatologist. If the nevus is constantly traumatized, as well as if there is a risk of its malignancy, removal of the nevus is indicated. Also, removal of a pigmented nevus of the skin can be done for cosmetic reasons. Nevus removal is performed by laser, surgical excision and radio wave method. Cryodestruction and electrocoagulation are not used due to the risk of possible trauma or incomplete removal, and also because this can stimulate malignant growth.

In any case, if you find a dark-colored raised area on your body, you should not try to get rid of it yourself. Consult a dermatologist to determine further tactics for removing pigmented nevus on the skin.

There are several types of nevi. Just like moles, nevi are a fairly heterogeneous group of skin tumors. But, if moles are more likely a popular term. Nevi are a group identified by doctors. Some nevi are formed due to the growth of skin pigment cells - melanocytes, which are responsible for coloring. Accordingly, these types will be called pigmented, melanocytic nevi, or even melanoform. Some nevi are formed not by melanocytes at all, but by cells of other types. In this case, they are hamartomas in nature. That is, a community of cells with impaired differentiation and tissue structure. These nevi are given a specific name; they cannot be called pigmented. Over time, only a pigmented nevus can turn into melanoma. Skin hamartomas (primarily nevus sebaceous) can give rise to various types of skin cancer. Due to the fact that nevi, in the vast majority of cases, do not threaten health, many doctors do not know their classification and differences from each other. Anything in a row is called a nevus, including seborrheic keratosis and pigmented papillomas. As a result, the group called “nevi” becomes only slightly more ordered than “moles”. The terms pigmented and pigmented should be distinguished, pigmented indicates the presence of pigment cells in the composition, pigmented indicates a darker color.

Pigmented nevus (melanocytic).

Melanocytes in pigmented nevi appear due to genetic errors leading to improper distribution and/or excessive reproduction; this can begin before birth or appear after birth. Depending on the depth at which melanocytes lie. It depends on whether the tumor is congenital or develops over time. And also, from external signs, there is a division into several types of pigmented nevi. The most common are ordinary acquired melanocytic nevi. They are divided into 3 subtypes: borderline, complex, intradermal. It is believed that they can pass into each other only in one direction: from borderline to complex, from complex to intradermal. This happens over many years and is accompanied by the movement of melanocytes from the deep layers of the epidermis even deeper into the dermis. At the same time, the nevus itself loses color, but it soft fabrics are becoming more prominent. Many melanocytes die on their own when they move into the dermis.

Borderline nevus of the skin.

The usual borderline acquired pigmented nevus is the most common starting variety, in which the majority of acquired nevi appear. Accordingly, they are more common in childhood. Melanocytes lie in the lower layers of the epidermis, at the border with the dermis. In fact, that’s why they are called borderline. The density of melanocytes here is quite high. Such moles more often turn into melanoma than complex or intradermal ones. They look like flat dark spots. The color should be uniform brown or black. Oval or round shape. With smooth regular edges. If a mole of this type grows more than 1 cm, the tumor is a dysplastic nevus or melanoma, that is, it requires mandatory removal.

Complex skin nevus.

A complex pigmented nevus becomes complex after some of the melanocytes move deeper into the dermis, while the other part remains in the deep layers of the epidermis. Hence, the bifurcation of external signs. On the one hand there is a flat component at the base, on the other there is a protruding component in the center. A particular type of complex nevus is papillomatous. Sometimes, there are more original varieties. Some part may simply have a different color, the nevus may consist of 2 different halves, part of the nevus may be slightly depressed. In this case, the mole becomes very similar to skin melanoma, which requires removal of the nevus and examination under a microscope (biopsy) to exclude it.

Borderline nevus in the form of a flat brown spot on the foot. The borders appear uneven due to the skin pattern.

The complex pigmented nevus in the photo has a soft protruding part and a flat part at the base.

Intradermal skin nevus.

Intradermal nevus is the final stage of development of acquired melanocytic nevi. At the same time, all pigment cells pass into the papillomatous layer of the dermis, causing proliferation connective tissue, which makes up the dermis. At the same time, some of the pigment cells die. Externally, this is manifested by an increase in the height of the growth and loss of its color. Most of these moles appear on the face, where they cause cosmetic problems. They can be called papillomas, growths, warts, wen. Try to remove something yourself. However, self-medication or removal by an unqualified specialist is dangerous, since melanocytes remain, and if they are injured and not completely removed, melanoma can develop. Although, the risk of developing melanoma from an intradermal nevus is extremely low.

Congenital or congenital pigmented nevus.

Not only congenital pigmented nevus is noted already at birth, but also moles from the hamartoma series (epidermal, sebaceous). Essentially, the Latin term “congenital” means congenital, however, to designate a melanocytic formation, it is better to use the Latin term to avoid even greater confusion. Congenital pigmented nevi appear very early during fetal development. They have features of melanocytic lesions with elements of hamartomas, that is, incorrectly developed cells, not only melanocytes, but other types. They may not appear immediately; over time they become darker and more elevated. Melanocytes lie in them at random, at different depths. Hence the heterogeneity in external manifestations, even within the same education. Often, lumpy, nodular, covered with dark long hair. Moles are divided by size into small (up to 1.5 cm), medium (from 1.5 to 20 cm), and large (from 20 cm). The larger the congenital nevus, the greater the risk of developing melanoma. Considering the heterogeneity of the nevus and its large size, melanoma can be detected on early stage not always possible. Plus, an unpleasant appearance, the presence of thick hairline make him serious cosmetic problem. Most often, such formations are simply observed for melanoma. Suspicious lesions can always be taken by incisional biopsy for histology. Removing a nevus is not always possible.

Intradermal melanocytic nevus. It is the final stage of development. It looks like a flesh-colored lump, covered with hair.

The photo shows a congenital (congenital) pigmented nevus. It has uneven coloring with bumps and hair.

Dysplastic skin nevus (atypical).

Dysplastic nevus, or atypical, is a melanocytic skin tumor that has abnormalities in appearance And histological structure. Most often, a dysplastic nevus is a modified borderline or complex acquired nevus. Rarely, such a nevus becomes congenital. Most dysplastic nevi have irregular shape, not covered with hair, almost flat. They have uneven coloring. Or, fuzzy edges. The appearance of any of the listed signs is enough to classify the nevus as dysplastic. Such moles can lead to melanoma over time. In addition, melanoma itself may initially have a similar appearance. Dysplastic nevus does not change throughout life; this is its main difference from melanoma. Such moles should be doubly observed, and the most suspicious ones should be removed. Especially if the patient’s family, or the patient himself, previously had skin melanoma.

Setton's nevus is a mole with a rim.

This is a pigmented nevus with a rim of white skin around the edges. The surrounding skin becomes white due to the erroneous action of the immune system directed against pigment cells. The nevus in the center is most often a borderline pigmented or complex nevus. Less commonly, there is a congenital, dysplastic or papillomatous growth in the center of the mole. Gradual whitening of the skin appears over several months. The central nevus may shrink and disappear within months or years. Remaining White spot gradually restores its color. Quite often, skin melanoma similar to Setton's nevus occurs; first of all, it must be excluded.

Nevus of Reed.

Reed's nevus looks like a flat or slightly raised plaque. Almost black, uniform in color. It has no hair, the surface is smooth. In its structure it is a borderline or complex melanocytic nevus. But, due to its dense black color and quick appearance raises suspicion of melanoma among doctors and patients. Therefore, such moles are removed for histological examination.

Papillomatous nevus of the skin.

Papillomatous nevus is another pigmented nevus, isolated on the basis of its external resemblance to papillomas. It has the structure of a complex or intradermal acquired melanocytic nevus. Soft, elastic, however, may have scales and crusts on the surface. It is necessary to distinguish between papillomatous and verrucous nevi. Wart has a completely different structure; it affects only the superficial layers of the skin. It is smaller in size, denser and rougher. Refers to hamartomas.

Spotted skin nevus.

It looks like a brown spot with multiple granular lesions. The spot itself is formed by pigment cells. Granular lesions have the structure of borderline or complex nevi. The sizes of these moles range from 1 to 4 cm. Sometimes, within a spotted nevus, you can also find a blue nevus, a Spitz nevus, or a dysplastic nevus.

Nevus Spitz.

A Spitz nevus appears as a reddish, brownish, or pink bump on the skin. Most often, it occurs in children. Appears out of nowhere. Grows quickly within months. Then, growth stops, and education continues for life. This pigmented nevus has many vessels, which leads to a resemblance to melanoma even under a microscope. In addition, there is a type of melanoma - Spitz melanoma, which is very difficult to distinguish both externally and under a microscope. However, unlike Spitz nevus, Spitz melanoma can lead to the death of the patient. If there is no certainty about the histological diagnosis, such moles should be treated as melanoma. That is, delete with a large margin.

Deramal melanocytic nevi.

These are nevi of Ota, Ito, Mongolian spot and blue nevus. Their pigment cells lie deep in the dermis (deeper than those of intradermal nevi). Because of this, they absorb light differently, which gives different shades of blue, gray, and light blue. In Russia, blue nevus is most often found. Other types of dermal pigmented moles rare, distributed only in Southeast Asia.

A blue nevus looks like a symmetrical round bump or bump. Dense, smooth to the touch. Dimensions from 5 mm to 1 cm. Honeycomb blue nevus is a type in the form of a plaque with nodules about 1 to 3 cm in diameter. It occurs most often on the scalp and buttocks. The frequency of occurrence of ordinary blue and honeycomb nevi is in the ratio of 5 to 1. Due to their rapid appearance and unusual color, blue nevi raise suspicion of melanoma. Melanoma from such formations develops infrequently, mainly from the honeycomb variety and on the scalp. Blue nevus melanoma tends to grow rapidly, often reaching several centimeters in diameter. It may look like a plaque with many nodules.

Skin nevi such as hamartoma (sebaceous, verrucous, Becker's).

Skin hamartomas are formations that appear from errors during embryonic development. Characterized by incorrect location various types cells (epidermis, vascular glands, etc.) relative to each other and with impaired cell maturation.

Sebaceous nevus or seborrheic.

Sebaceous nevus (seborrheic) is a large mole with a disturbed structure of many types of cells at once: epidermis, hair follicles, sebaceous glands, sweat glands. Noticeable already at birth or discovered later. The size of a sebaceous nevus is from 1 to 6 cm. The surface is often smooth, lumpy, waxy with a yellowish or orange tint. There is no hair. With age, from flat it becomes more and more convex and lumpy. Most common on the head, upper half chest. The main danger of such moles is increased likelihood development of other skin tumors on their surface. Most often these are benign trichoblastoma and syringocystadenoma of the skin, but many others also occur rare tumors. Malignant basal cell carcinoma develops with a frequency of 1 to 10% according to various authors. Removal of a sebaceous nevus with a laser or cryodestruction significantly improves the cosmetic result, however, it does not completely eliminate the appearance secondary tumors. Removal with a scalpel can lead to disfiguring scars, but it eliminates the appearance of secondary formations as much as possible.

In the photo there is a seborrheic or sebaceous nevus in the shape of the letter V. It can serve as a source of malignant and benign tumors.

The photo shows a blue nevus of the hand. It is rather gray in color. Firm to the touch.

Warty skin nevus.

As mentioned above, this formation should not be confused with papillomatous nevus. A verrucous nevus is essentially a hamartoma that affects only the epidermis. Despite the fact that it is formed during embryogenesis, it resembles a wart not only externally, but also under a microscope. The mole has the appearance of tubercles and plaques with horny overlays and processes. The tubercles often form lines. A warty nevus does not increase the risk of cancer and does not develop into anything. Mole removal is possible with laser, liquid nitrogen, electrocoagulation and radio wave method.

Becker's nevus.

Becker's nevus is another hamartoma affecting hair follicles, skin fibers and blood vessels. There are very few melanocytes in it; the color is due to a change in the orientation of the dense fibers of the skin. The size of the mole is from 10 to 15 cm. Becker's nevus is divided into a colored part and a part covered with hair. They do not completely overlap each other; in some places one or the other may be present. Differs from congenital nevus flat surface under the hair, absence of tubercles and seals. With age, the mole becomes more noticeable due to hair growth and darker coloring. Does not increase the likelihood of skin cancer, but can be combined with underdevelopment of muscles and skeleton on the side of the formation. Acceptable cosmetic treatment to reduce hair growth and color intensity. Complete removal for large sizes is impractical.

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Every person has moles or nevi on their body. light color skin. 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 usually appear in early childhood and remain with the person for life. The following symptoms are characteristic of intradermal or intradermal melanocytic nevus:

• color uniformity throughout life;
• absence discomfort 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:

• ultraviolet radiation;
• phototherapy;
• severe skin damage;
• burns;
• some dermatological diseases;
• hormonal disorders;
• immunodeficiency.

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 of hormonal changes in the 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.

Noticing that after a mole is damaged there's blood coming out, it is important to carry out antiseptic treatment in a timely manner 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 exposed areas of the 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 such a benign formation on the skin causes discomfort, you should definitely consult a doctor about the possibility of removing it.