Nevi: main types, principles of diagnosis, prevention of melanoma. Nevus complex (mixed) - clinical picture, diagnosis, prognosis

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 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 special attention to the area with the formation. 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 and solariums;
2. promptly remove suspicious moles if they are located in traumatic areas;
3. review regularly nevus for changes in color or shape.

Difficult pigmented nevus is a benign formation in the form pigment spot Brown, which is located simultaneously in two layers of the skin - epidermal and dermal. Externally, a nevus resembles a small wart (no more than a centimeter in diameter) or a papule rising above the skin. The nevus begins its growth in the upper layers of the skin, and then gradually grows into the dermis. Although this type nevus is benign education skin, according to some data it can transform into melanoma (in 50-80% of cases).

Symptoms of complex pigmented nevus

A complex pigmented nevus is distinguished by a warty or smooth surface, on which the growth of bristly hair is often present. The nevus is located in two layers skin, therefore combines the characteristics of intraepidermal and intradermal. The epidermal component causes its brown color, and the presence of an intradermal component contributes to its raised appearance above the skin level. A complex nevus will rarely reach a large size.

Diagnosis of complex pigmented nevus

A dermatologist can diagnose a nevus based on a preliminary examination. Timely diagnosis nevus is the key to quick and successful treatment. In order to determine the depth and extent of nevus growth into the dermis, the doctor may prescribe an ultrasound of the skin formation. During the examination, the doctor interviews the patient, finding out exactly when the formation occurred, whether its appearance, size, shape and color have changed, as well as the reasons for the changes themselves. It turns out whether there were attempts at treatment and what exactly the previous treatment was? If melanoma is suspected, immediate consultation with an oncologist is necessary. Carrying out a biopsy of a nevus is very dangerous; injury to the nevus can develop into malignancy. It is for this reason that histological examination is carried out after its removal.

Today there is new method diagnosing nevi - epiluminescent microscopy. This method diagnosis is carried out using a special optical device with artificial lighting. The study takes place directly on the surface of the skin. Apply a couple of drops to the nevus vegetable oil in order to create the effect of epiluminescence, then the device is placed on the neoplasm. This research method will not damage the nevus and is therefore the most accurate in determining the structure of the neoplasm. This study called dermatoscopy.

The computer diagnostic method is also widely used in such studies. Thanks to a digital video camera, the image of the pigment formation is recorded and stored in the computer memory. There is a special computer program, which processes the received information and compares it with the database, ultimately producing an accurate conclusion.

Treatment of complex pigmented nevus

This disease requires mandatory observation by a dermatologist. Treatment of pigmented nevus is a strictly individual procedure. The treatment method is selected by the doctor for each specific case. Before consulting a doctor, do not use ointments. There is no point in delaying treatment or going to the doctor, as there is Great chance that every year the spot will increase in size. The indication for its removal is permanent injury or the appearance characteristic features malignancy. Removal may also be done for cosmetic reasons. There are several ways to remove a nevus:

• using a laser;
• radio wave method;
• surgical excision;
• electrocoagulation;
• cryodestruction.

Cryodestruction and electrocoegulation are used very rarely due to the fact that during the removal process the nevus may not be completely eliminated, and also because of the risk of traumatizing it, which can later develop into malignant growth.

Removing a nevus with a laser does not make it possible to study the nevus in a histological examination after elimination. It is most advisable to use the radio wave method or surgical excision for removal, since they guarantee complete removal of nevus cells, which is of great importance for preventing the development of melanoma.

The surgical method is most suitable when the nevus is deep in the skin. The disadvantage of this method of elimination is the postoperative scar, since the nevus is removed along with the adjacent skin. According to oncological requirements, the diameter of the removed surface should be 3-5 cm.

If a nevus is detected, you should immediately consult a doctor for advice. Under no circumstances should you excise a nevus yourself, since injury to it leads to the development of a malignant tumor. According to statistics, in men melanoma more often develops on the back, and in women on lower limbs. To prevent the appearance of melanoma, you need to stay under the sun as little as possible, avoid solariums, and also carefully monitor existing moles. The first time their shape or size changes, you should immediately consult a doctor. There are many known cases that ended fatal due to self-medication and the reluctance of patients to seek medical help in a timely manner.

Synonyms of complex nevus: mixed nevus.

Definition. Acquired pigmented nevus, the nevus cells of which are located both in the epidermis and in the dermis. It has the clinical features of borderline and intradermal nevi.

Age and gender. Occurs in adolescence. Gender doesn't matter.

Elements of the rash of a complex nevus. A tumor-like formation in the form of a papule or node, usually less than 1 cm in size. The surface is smooth, less often warty, keratinized, often with the growth of bristly hair. In shape, complex nevomelanocytic nevi are predominantly uniformly elevated formations. Various clinical options complex nevi discussed in detail in the third chapter of this atlas.

The color is usually uniform: dark brown, sometimes almost black. In the presence of an intraepidermal component, the nevus is usually dark in color. During the transformation of a complex nevus into intradermal color may be uneven.

Localization any.

Histology. Combines the histological features of borderline and intradermal nevi. Nests of nevus cells are located both in the epidermis and in the skin itself. Nevomelanocytes, which migrated into the dermis more or less evenly over the entire area of ​​the nevus, are determined in the form of nests mainly in the papillary layer of the dermis.

Differential clinical diagnosis complex nevus carried out together with intradermal melanocytic nevus, since these two neoplasms are almost impossible to distinguish from each other. However, some Clinical signs allow you to do this. Firstly, a complex nevus is more characterized by the preservation of a pronounced skin pattern on the surface, secondly, it is darker and, thirdly, it is less elevated than an intradermal nevus.

Forecast. Complex nevi rarely transform into melanoma.

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Pigmented nevus is a fairly common skin disease, which often has a benign course. In some cases, it may form on the mucous membrane oral cavity, eyes and genitals. The causes of age spots remain not fully known, but experts in the field of dermatology have found that congenital and acquired nevi can develop due to completely different predisposing factors.

The clinical picture is limited only to the appearance of moles various localizations and sizes. Symptoms in the form of pain, itching, burning and bleeding occur in cases where the formation degenerates into oncology.

The type of nevus can be determined both through a physical examination and through specific laboratory and instrumental examinations. Removal of the tumor is carried out using microsurgical medical intervention.

In the international classification of diseases, such pathology is represented by several meanings. The ICD-10 code will differ depending on the form of the disease - melanoform nevus - D22, congenital - Q5, non-tumor - I1.

Etiology

Clinicians assume that the formation of all pigment spots occurs during intrauterine development of the fetus, which means that congenital pigmented nevus can be caused by the following predisposing factors:

• genetic predisposition;
• incorrect cell division process;
• influence on the pregnant woman’s body of toxic substances or ionizing radiation;
• the expectant mother's addiction to bad habits, in particular to drinking alcohol and smoking cigarettes;
• organ diseases suffered during pregnancy genitourinary system;
• the course of venereal diseases.

Acquired moles also have innate character However, they are expressed not from the moment of birth, but throughout life due to the influence of unfavorable factors, which is why they are usually called secondary.

The appearance of new moles can be triggered by:

• violation hormonal levels, which is often observed during puberty, pregnancy or, and also develops due to uncontrolled intake oral contraceptives;
• prolonged and regular exposure of the skin to ultraviolet radiation or direct sunlight;
• any disease that reduces resistance immune system;
• wide range viral skin pathologies;
• stressful situations or emotional exhaustion;
• the presence of a close relative in the medical history, which is considered skin cancer.

It is noteworthy that congenital pigmented nevus in a child is diagnosed only in 5% of cases. Most often, moles appear from puberty to age thirty-five. Another peculiarity is that in older people, pigment spots may be completely absent.

Classification

In appearance, pigmented nevi are:

Types of the disease according to the stages of development of the neoplasm:

• growth within the epithelium;
• accumulation of nevus tissue at the border between top layer skin and the skin itself;
• intradermal pigmented nevus.

Groups of moles that differ in size:

• small - in such cases, the volume of neoplasms varies from five millimeters to one and a half centimeters;
• medium - from 1.5 centimeters to five centimeters;
• large - from five to ten centimeters;
• giant pigmented nevi - are such if their diameter exceeds ten centimeters. In some cases they can reach 20 cm.

The most common forms of acquired disease:

• borderline pigmented nevus- it is characterized by a black or brown tint, the absence of clear boundaries and elevation above the skin. Often there is no threat of malignancy, but it can develop into a complex nevus. It can be either acquired or congenital;
• complex pigmented nevus- practically no different from the previous form, except that it rises above the skin. Because of this, it has the appearance of a papule, which is why it is also called papillomatous nevus;
• intradermal pigmented nevus- covers a large area of ​​skin, and also has hairs on its surface;
• dysplastic pigmented nevus- can be an independent form, but very often acts as a modified mole of one of the above types. It is characterized by the presence of unclear boundaries, uneven color and irregular shape. What is noteworthy is that it is considered a precancerous condition.

Rarer forms of acquired pigmented nevus are presented:

• balloon nevus- this mole got its name because upon microscopic examination it resembles a bloated container. Often it is intradermal, less often it acts as a complex nevus;
• Setton's nevus- looks like a dark area of ​​skin surrounded by a light halo. Sometimes it can disappear without a trace on its own, leaving behind a discolored spot. This variety is not melanoma-hazardous;
• spindle cell nevus- very often localized on the face and looks like a papillomatous mole;
• blue nevus- in this case, nevocytes lie very deep in the skin, which causes a specific appearance. Malignancy is extremely susceptible to in rare cases;
• Mongolian spot;
• flaming nevus.

As separate form a pigmented nevus appears on the eye - this type is practically not dangerous. It can be localized on the conjunctiva and is then clearly visible even to the naked eye. Occurs less frequently in choroid retina, but is detected only during an examination by an ophthalmologist. Eye nevi are:

• stationary, i.e., not changing as the organism matures;
• progressive - characterized by slow growth and over time can lead to a narrowing of the fields and a decrease in visual acuity.

Symptoms

The basis of the clinical picture is the actual formation of pigmented areas of the skin. It is not uncommon that a congenital or acquired nevus can be supplemented by the presence of hairs, which can be single or multiple. They are darker and stiffer in comparison with other vellus hairs covering the human body.

Most often, pigmented nevus of the skin is localized on:

• face and upper limbs;
• scalp - this is most typical for papillomatous moles;
• back and buttocks;
• lower back and shoulder girdle;
• eyes.

Emergence additional symptoms indicates the degeneration of a benign nevus into a malignant melanoma. The malignancy process can be affected by:

• prolonged exposure to direct sunlight;
• injury to a mole;
• friction against clothes;
• chemical damage spots.

The process of malignancy is accompanied by the following symptoms:

• rapid growth in the number or volume of pigment spots;
• change in the contours and shade of the mole;
• the appearance of a dark halo around the nevus;
• accession inflammatory process, which is accompanied by redness and swelling of the skin tissue surrounding the spot;
• discharge of blood or other pathological fluids;
• formation of a crust over the nevus;
• causeless peeling of the skin in the affected area;
• pain syndrome varying degrees expressiveness;
• addition of itching, tingling and burning.

If one or more of the above symptoms occur, you should seek qualified help as soon as possible for immediate removal of the nevus.

Diagnostics

A dermatologist can differentiate the type of such skin neoplasm based on the results laboratory research and instrumental examinations.

However, before carrying out specific diagnostics The clinician should undertake several general activities:

• studying the medical history of the patient and his close relatives;
• collection and analysis of the patient’s life history;
• a thorough physical examination of the problem area;
• a detailed survey of the patient or his parents - to establish the first time of appearance and severity of additional symptoms.

You can confirm the diagnosis using:

• fluorescence microscopy;
• microscopic examination of a scraping from the surface of a mole - only in cases of pathological fluid discharge from the nevus;
• dermatoscopy using a magnifying glass and a camera;
• biopsies;
• biochemical analysis blood - to determine the presence of tumor markers;
• CT and MRI of the affected area;
• SIAscopies.

In addition, consultation with an ophthalmologist may be required.

Treatment

The treatment regimen is determined by the nature of the disease. For example, in the absence of signs of malignancy and a person’s psychological discomfort from the presence of a nevus, they turn to wait-and-see tactics - this means that treatment is temporarily postponed.

However, when high risk malignancy, pigmented nevi are removed by microsurgical interventions. Currently, operations are carried out in several ways:

• laser evaporation;
• electrocoagulation;
• cryodestruction;
• radio wave knife.

Sometimes, with a complex pigmented nevus, they resort to surgical excision using a scalpel. In this case, not only the mole is removed, but also part subcutaneous tissue. Regardless of the choice of method, after the procedure a crust forms at the site of the nevus, which is strictly forbidden to be torn off and wet - it disappears on its own two weeks after the operation.

Prevention

Specially designed preventive measures that prevent the occurrence of pigmented nevus have not been developed. To avoid problems with the development of a mole, it is recommended:

• avoid prolonged skin contact with sun rays or ultraviolet radiation;
• treat the skin with specially targeted products to protect it during prolonged exposure to the sun;
• refusal to visit the solarium for those who have multiple age spots and have relatives with melanoma;
• prevent injury to the mole;
• complete every year medical examination, including a dermatologist.

The prognosis of pigmented nevus in children and adults is often favorable. Moreover, even after undergoing microsurgical surgery to remove malignant mole, the outcome will be positive.

Nevus (synonyms: mole, birthmark, age spot) is a benign skin formation characterized by the appearance of hyperpigmentation spots on the skin. Pigment spots are very diverse in shape, size and color. The size of nevi ranges from one or two millimeters in diameter to huge spots irregular shape sizes 10-20 centimeters. Pigmented nevi may not rise above the skin at all, be somewhat convex and even resemble. Their color ranges from flesh to dark brown, almost black.

A nevus is a local accumulation of pigment cells - nevocytes, which are pathologically altered melanocytes responsible for normal skin color. The main difference between nevocytes and melanocytes is the huge concentration of melanin (natural pigment), several tens of times higher than normal.
It is believed that pigmented nevus is a congenital malformation in which the migration of melanoblasts (the precursors of melanocytes and nevocytes) is disrupted. As a result, melanoblasts form compact clusters in the skin, which then turn into nevi. The division of nevi into congenital and acquired is very arbitrary; many scientists believe that acquired nevi that occur in adults do not form anew, they simply appear over time. The following predisposing conditions for the occurrence of congenital melanocytic nevi in ​​children can be identified:

• exposure of a pregnant woman to radiation or toxic compounds;
• diseases of the urogenital tract in a pregnant woman;
• pathology of pregnancy, occurring with pronounced fluctuations in hormonal levels (threat of miscarriage, toxicosis);
• genetic predisposition.

Acquired nevi appear throughout life. Provoking factors may be:

How common are nevi: epidemiology

Up to 10% of children are already born with birthmarks(nevi). IN puberty nevi are observed in 95% of adolescents. By the age of 25-30, the number of nevi in ​​one person averages 35-40 pieces. Further, with age, there is a tendency towards a decrease in the number of nevi, and by the age of 85-90, single formations remain on the body.

Classification of nevi

There is a generally accepted international classification, according to which there are several groups of nevi, and each of these groups has a number of its own varieties. The main forms of neoplasms include:

1. Melanocytic nevi epidermal origin.
2. Melanocytic nevi of dermal origin.
3. Benign dermal melanoses.
4. Congenital melanocytic nevi.
5. Dysplastic melanocytic nevus or Clark's nevus.
6. Other nevus-like formations.

Melanocytic nevi of epidermal origin

This is the most common type of nevi. Melanocytic nevi are acquired; on average, each person has from 5 to 15 such formations. Appearance: round or oval shape with clear edges; smooth or slightly papillomatous surface; color from reddish to brown. The melanocytic type of formations can manifest itself in following types:

• - so named because of the peculiarities of the localization of new cells - at the border of the epidermis and dermis. It looks like a flat spot, localized on the body - in any area.

• (this is what is most often called a mole) - it looks like a dome-shaped formation with a color ranging from light brown to almost black. May be covered with hair. Over time, as it grows, this nevus can become covered with papillomatous growths (papillomatous nevus), and also connect to the skin only with a thin stalk.

• - represents transitional form between the two previous types. Looks like a small papule with papillomatosis. It is extremely rare for the size to be more than 1 cm.

• (Setton nevus) is a special type of pigmented neoplasm that looks like a pigment spot with a surrounding depigmentation zone. This zone is 2-3 times wider than the nevus itself. It occurs most often in teenagers and pregnant women and may disappear over time.

• Balloon cell nevus- a rare type of nevus. It is practically no different from ordinary moles, but consists of special balloon-shaped cells. The diagnosis is made only on the basis of histological examination.
• Recurrent melanocytic nevus, also called pseudomelanoma, is formed as a result of incomplete removal of dermal or complex nevi. In this case, after a few weeks or months, a new one grows at the site of the removed tumor, usually even larger.
• Spitz nevus (synonyms: spindle cell, epithelioid). Characteristic of children, it is a single hemispherical nodule that is dense to the touch. Color: pink or brownish with a red tint. A variation is Reed's nevus, which is a formation 3-10 mm in diameter in the form of a blue-black papule with clear edges. The classic location is the hips and legs in women.

Melanocytic nevi of dermal origin

In this case, melanocytes of the dermis become the source of nevocytes. This variety is also characterized by a multiplicity of manifestations:

• – looks like a single nodule up to 10 mm in size, color – from gray to black with a bluish tint. The surface of the nevus is smooth and hair does not grow on it. Typical localization: face, hands, neck. Found on the mucous membranes of the vagina and mouth.

Benign dermal melanoses

These are the closest “relatives” of blue nevi, having a typical appearance. The following types of dermal melanosis are found:

• - delimited spot oval shape, up to 10 cm in size, grayish-bluish or brown in color, localized in the lumbosacral region. Occurs in 80% of children of Mongoloid and Negroid races and only 1% of Caucasians. Usually disappears by 8-13 years.

• Nevus of Ota (Ota) is a pronounced pigmentation of the skin around the eyes and sclera. Looks like more dark spots, located on one side of the face and prone to merging. Typical for girls of the Mongoloid and Negroid races.

• Nevus of Ito - almost no different from nevus of Ota, but localized on the lateral surface of the neck, in the supraclavicular region, near the scapula.

Congenital melanocytic nevi

Synonyms for this type are verrucous or giant nevus. They occur in 1% of newborns. They can be represented by a variety of elements: papillomatous, papular, nodular. They are determined immediately after the birth of the child or after a few weeks. By size they are distinguished:

• small – up to 1.5 cm;
• medium – 1.5-20 cm;
• giant - more than 20 cm.

Giant nevi often resemble the shape of “panties”, a bathing suit, or are arranged in the form of a “leopard skin”. They grow with the child.

Dysplastic melanocytic nevus or Clark's nevus

This is the most unfavorable nevus in terms of malignancy, a frequent precursor to melanoma. It usually appears before puberty, and new elements appear until old age. It looks like spots of irregular shape, up to 5 cm in size. The borders are often irregular, and a zone of hyperemia (redness) may be noted along the edge. Favorite places to appear: head, back, lower back, buttocks and other places that are constantly closed from contact sunlight.

Other nevus-like formations

There are other skin formations that are also called nevi, but, in fact, are not them. This:

• hemangiomas;
• teratomas;
• sebaceous nevi - formations, most often localized on the head, resembling nevi, but not containing new cells and melanin;
• vascular nevi - areas of the skin that are depleted of blood vessels and therefore have a paler color.

Others are also classified as nevi benign tumors skins that do not contain nevocytes and melanin in their structure - the so-called epidermal nevi. note: The main difference between epidermal nevi and moles is the absence of melanin-containing cells in their structure. The causes of neoplasms are the same, but the source of the tumor is other skin cells. Types of epidermal nevi:

• papillomatous soft nevus - is a small soft plaque, almost indistinguishable in color from normal skin;

• warty epidermal nevus is most often a congenital neoplasm. It has the appearance of dense warty tumors of a grayish or brownish color, ranging in size from 1 to 4 cm. The characteristic location is the limbs, especially along the nerves and large vessels;

• Darier-like epidermal nevus. So named because of its resemblance to skin rashes with Darier's disease. It looks like keratinized papules, also covered with crusts;

• Haley-Hailey-like nevus is also named due to the similarity of the lesions to clinical picture Haley-Hailey familial pemphigus. Manifests itself as inflammatory plaques with erosions and blisters;

Diagnostics

You should know that, based on the photo, nevi can be extremely difficult to distinguish from each other. Other diagnostic methods help to definitively determine the type of nevus. It is necessary to examine moles in order to identify dangerous nevi and prevent their transformation into a malignant tumor - melanoma. Diagnosis begins with a conversation between the dermato-oncologist and the patient. During the conversation, the doctor establishes the following facts:

• how long ago the formation appeared, is it acquired or congenital;
• whether the appearance (color, size, borders) of the nevus has changed;
• what caused the changes - burns, injuries, scratching, attempts at removal;
• whether removal attempts were made and what method was used.

The nevus must be measured and its shape, color and other characteristics described. Important!Biopsy of nevi with diagnostic purpose not fulfilled! Any traumatic effect on the nevus can provoke its malignancy, therefore histological examination is carried out only after complete removal of the nevus. In some cases, the method of taking a smear from the surface of the nevus can be used if there are cracks on it. It is recommended to perform such a study in specialized oncology centers where it is possible to perform radical removal nevus immediately after receiving the test result. Most effective way The study of nevi before removal is epiluminescence microscopy. The essence of the method is to study the nevus under a microscope directly on a person. To do this, oil is applied to the neoplasm, which provides an epiluminescence (illumination) effect, and then the nevus is examined through the oil through a dermatoscope.
It's becoming more and more popular today computer diagnostics nevi, during which a photo of a nevus is compared with an extensive database of images. The result of computer analysis suggests the most likely type of nevus.

Complications of nevi

Large nevi can cause significant discomfort to a person due to constant irritation from clothing, which causes their damage. If damaged, there is itching in the area of ​​the nevus and bleeding from its surface. However, the most dangerous phenomenon What nevi can lead to is their transformation into a malignant tumor - melanoma. Not all nevi are dangerous in this regard; the most malignant and prone to transformation are blue nevus, nevus of Ota and dysplastic melanocytic nevus. There are some signs that significantly increase your risk of melanoma. Special attention must be addressed to:

• large congenital nevi;
• the appearance of nevi in ​​old age;
• a large number of nevi on the body - over 50 at a time;
• frequent appearance of new nevi;
• the location of the mole in a place where they are exposed to constant mechanical impact: on the neck, armpits, ankles, waist.

All nevi should be closely monitored, especially large ones and those located in inconvenient places, and if any of the following symptoms appear, you should immediately contact your oncologist. Signs of nevus degeneration:

1. Rapid growth - more than 1.5-2 times in a few weeks.
2. A rapid change in the color of the nevus, especially when it becomes black or dark blue.
3. Changes in the contours of the spot - smooth contours become scalloped, “ragged”.
4. “Smearing” of the borders of the nevus.
5. Bleeding or constant weeping of the mole.
6. Peeling of the skin over the nevus.

Prevention of malignancy of nevi

The danger of melanoma is that the tumor, even if small in size, tends to metastasize to the liver, brain and other organs. The mortality rate for this tumor is 45-50%, so it is better to try to prevent its occurrence. It is impossible to completely prevent the appearance of melanoma, but by adhering to simple recommendations, you can significantly reduce the risk of degeneration of a nevus tumor into melanoma.
So, recommendations for the prevention of melanoma:

1. Reduce the time your skin is exposed to sunlight. Avoid exposure to the sun during the period of its maximum activity - from 11 a.m. to 5 p.m.
2. Try to completely prevent ultraviolet radiation from reaching potentially dangerous nevi, including when visiting a solarium.