Many people do not know about the nature of moles and due to the fact that these formations do not bother them during their life, they do not even remember their existence. What is a nevus from a medical point of view? This is an accumulation of pigment cells on the surface or in a layer of the skin, which can be congenital or acquired. Such spots can be of different sizes - from 0.5 to 10 cm in diameter. Location on the body, the size of these formations was originally embedded in the human DNA and is already present in the newborn, but are not visible until a certain age.
Nevuses of the skin are acquired or congenital formations of a benign nature and consisting of accumulations of melanocytes. That is, this includes birthmarks or moles that any person has and are a malformation of dermal cells. Ordinary nevi are a very common occurrence that does not require any therapy and does not pose a threat to human he alth. However, they come in different types, some of them tend to degenerate into malignant tumors.
In addition, skin nevi are not alwayscongenital pathology, often they occur during life. As a rule, until a person comes of age, their size and number can increase, and then decrease slightly. This fact is due to the simultaneous growth of nevi along with the body. After the end of the period of growing up, the increase in moles also stops.
In accordance with the International Classification of Diseases (ICD), skin nevi have the code D22.
Causes of occurrence
The causes of moles are violations of the process of migration of melanoblasts, which are the precursors of melanocytes. As a result of such a violation, an area of \u200b\u200btheir significant concentration is formed, where a nevus of the skin subsequently occurs. Experts divide them into congenital and acquired, but some experts are of the opinion that such a classification is conditional. This opinion is connected with the fact that moles that arise in adults are not newly formed areas of melanoblast concentration, but congenital, but manifested only after a while.
The main reasons contributing to the formation of moles during fetal development include:
- Hereditary factor.
- Pathologies that accompany pregnancy (toxicosis, threatened miscarriage).
- Exposure to radiation and ionizing radiation.
- Exposure to allergic and toxic agents.
- Acute forms of infectious pathologies of the genitourinary system in pregnant women.
Provoking factors
Provoke developmentacquired moles can be the following factors:
- Exposure to the skin of ultraviolet radiation.
- Pregnancy with hormonal surges.
- Skin diseases of an infectious nature.
- Allergic skin diseases.
- Mechanical trauma to the skin.
- Using contraceptives.
- Hormonal surges during puberty.
Below, consider the main types of moles.
Varieties, classification
Acquired and congenital skin nevi may have a similar structure. This reason makes it appropriate to classify them according to their histological structure. This allows you to take into account the main features of each mole and, with a high probability, predict their subsequent development. Experts distinguish about 50 varieties of nevi, but about 10 of them are most common. First of all, all moles are usually classified into two varieties:
- Melanoma dangerous (melanomoform).
- Melanomaniac.
Formations of the second type almost never degenerate into malignant ones. Therefore, the recommendation to remove them is mostly cosmetic.
Melanoform skin nevi are characterized by a high probability of degeneration into a malignant tumor. Such formations are almost always recommended to be removed.
Among melanomaniacs, the following are distinguished:
- Intradermal pigment.
- Halonevus.
- Fibroepithelial.
- Papillomatous.
- Mongolian spots.
Mongolian spot
It is a pigmented nevus of the skin of a congenital type, most often found in newborns belonging to the Mongoloid race. This variety is inherently a genetic variant of a violation of the process of pigmentation of the dermis. For most people, the Mongolian spot disappears by the age of five. They are localized, as a rule, on the sacrum and buttocks. Sometimes the Mongolian spot persists for life rather than disappearing. But even in such cases, it does not degenerate into a malignant formation and does not require therapy.
Papillomatous appearance
Papillomatous nevus of the skin has an unsightly appearance, which often frightens its carriers. That is why people often consult with oncologists, suspecting the worst-case scenario. Papillomatous intradermal nevi of the skin are characterized by a strong elevation, a difference from the rest of the dermis in color and shape. The surface is lobular, brown. Such a nevus does not cause subjective sensations, except for psychological discomfort, if the place of its position is the hands, neck, face. A favorite place of localization is the scalp, limbs, torso. During life, papillomatous nevi change their characteristics. They can become a different color, increase in size, but rarely degenerate into malignant tumors.
Fibroepithelial nevi
The most common type of mole is fibroepithelial. It can be both congenital and acquired. Often suchnevi occur against the background of hormonal changes in the body. However, medicine has information about the occurrence of moles of this type in the elderly. Most often, fibroepithelial nevus has a rounded shape, pink color, elastic consistency. For some time, the mole grows, then this process slows down, and its progress stops. Cases of degeneration of fibroepithelial nevi are extremely rare.
Setton's nevus
Sometimes it is called halonevus. It is exclusively acquired, develops in people, with malfunctions of the hormonal system, autoimmune pathologies, reduced immunity. The reaction starts the development of halonevus, in which the body fights with its own cells. It is characterized by an oval shape, it rises slightly above the skin. The name of the nevus is consonant with its shape. The central part of the mole is more intensely pigmented than the edges. This color visually resembles a halo - an optical phenomenon that forms around the moon or sun. The central (main) part of the nevus is located inside the pale zone. It is not recommended to remove such formations, as they may indicate the presence of other, serious pathologies in the body. Halonevus almost never degenerate into a cancerous tumor.
Other varieties
Intradermal pigmented skin nevi most often develop during puberty. At the initial stages of their development, they are located inside the cover, they do not protrude on its surface. Usually nevi of thistypes are small in size, but over time they can change - change their own shape, color. They are not prone to progression in old age, which cannot be said about moles of other types. Only in rare cases do they degenerate into malignant tumors.
Many people wonder that this is a melanocytic nevus of the skin. It is customary to include the following varieties in this group:
- Blue.
- Giant pigment.
- Nevus Ota.
- Dysplastic.
- Border pigment.
Border pigment mole is most often a congenital neoplasm, but in some cases it can appear in the first years of a child's life. As a rule, nevi of this type grow in proportion to the growth of the body. If a person grows intensively, the size of the formation also increases greatly. Above the skin, such nevi rise slightly and are characterized by a high accumulation of melanin, which causes the dark color of the mole, which can be dark purple, dark brown, even black. This type of moles does not have a clear localization site; it can occur on any part of the body. A characteristic feature is that only borderline pigmented nevi can occur on the feet and palms. Its dense consistency may indicate malignancy.
Dysplastic nevi
Dysplastic skin nevi are both congenital and acquired. Moles of this type in many patients occur during puberty, are family in nature (often found in several family members). locatedthey are usually in the armpits, inguinal folds, on the hips, legs, and upper back. Skin nevi appear, as a rule, in a group, but there are cases of a single occurrence. The color of such spots can be different - from light brown to black. Quite often there is a peculiar pigmentation on the periphery and in the center of the spot. Accurate diagnosis involves a biopsy that allows you to detect a typical accumulation of cells for such a formation. In about 90% of cases, dysplastic nevi degenerate into malignant formations - melanomas. In this regard, the appearance of such a mole requires radical removal and appropriate therapy.
Nevus of Ota
Nevus Ota is characterized by a large accumulation of melanin. As a rule, such elements are of a single nature, however, there are also formations of a multiple nature, prone to merging. It is a neurocutaneous nevus. In this case, the formation of moles occurs under the influence of neurological factors. It is considered a nevus of the skin of the face - it is usually located along the edge of the orbit or on the cheekbones. It appears as a blue-black spot located in the cornea or on the white of the eye. A characteristic feature of the nevus of Ota is that it is able to change the mucous membranes of the eye, in particular, if it has a large size.
Such education is a congenital phenomenon and genetic etiology. It is most common in Mongolians and Japanese, less common in other Asians and Chinese. In a malignant nevus of Otatransforms infrequently, but such a possibility remains. Ultraviolet plays a significant role in rebirth.
Giant nevi
Giant pigmented nevi are congenital formations and, unlike other congenital birthmarks, are visible from birth. Progress as the body grows and reaches a significant size. Often, such a formation is not just localized in a large area of \u200b\u200bthe dermis, but occupies the entire anatomical region, for example, the trunk, neck, half of the face. Medicine has recorded cases when the size of giant pigmented nevi reached 40 cm. In such a situation, we can talk about a significant cosmetic defect, since the mole protrudes strongly above the surface of the dermis and is considered as a massive tumor that worsens the appearance of a person. The color of the spot in most cases varies from gray to brown. Its structure can be varied, for example, small warts, furrows, cracks can be located on its surface, increased hairiness can be observed. It is these characteristics that distinguish giant pigmented nevi from other types.
Therapy of such formations is carried out in order to remove a cosmetic defect. Only in rare cases is its malignancy observed. Often this happens after it is removed. However, doctors say that a nevus of such a large size is often injured, and this, in turn, contributes to its rebirth. It is removed by surgical excision of the tumor and subsequent skin grafting.
Blue nevus
It is a benign formation, although it indicates a precancerous condition. Their name is due to the color. However, moles can be not only blue, but also black, dark purple, gray, dark blue, blue. Blue nevi consist of a significant accumulation of melanocytes that actively produce melatonin. As a rule, they are single, but there are also multiple rashes. Above the skin, such moles protrude slightly, and palpation of the formation reveals an intradermal node of a dense structure. Such a nevus does not have a clear localization, it can occur in any area. Its boundaries are clear, the diameter does not exceed a centimeter, there is no hair growth on it. The degeneration of the blue nevus occurs, as a rule, as a result of constant trauma or after incomplete removal. It is worth noting that the transformation itself is very rare.
Diagnosis of moles
The main task of the process of diagnosing skin nevi (according to the ICD code D22) is the differentiation of education with melanoma and other diseases of the dermis of a malignant nature. In this regard, the dermatologist-oncologist will first of all have to exclude the malignant form of the pathology, and then determine the type and appropriate therapy.
For this purpose, the following diagnostic methods are used:
- Echography.
- Histological examination.
- Biopsy.
- Termometry.
- Phosphorus isotope diagnostics.
- Dermatoscopy.
Dermatoscopy is performed withusing a special apparatus that magnifies the image tenfold and allows you to detect the slightest changes on the surface of the nevus. Currently, this technique is the most effective in the early diagnosis of melanoma. However, dermatoscopy does not allow to refute or confirm the diagnosis with full confidence, but can only prompt the doctor for the subsequent diagnostic tactics. The diagnostic method is absolutely painless, as it is non-contact and does not involve any effect on the patient's skin.
Phosphorus isotope diagnosis involves the accumulation of radioactive phosphorus by malignancy. In melanoma, this substance accumulates in nevi, which indicates increased cell division in its structure and suggests the presence of cancer.
Thermometry involves local measurement of the temperature of the dermis. The procedure is carried out using a special apparatus. During the study, the temperature on the surface of a he althy dermis is compared with the temperature on the surface of the skin nevus (according to ICD 10 code - D22). If the formation is benign, then the difference in indicators will be about one degree, and if it is malignant, it will be about 2-2.5 degrees.
The most reliable diagnostic method is a biopsy, which involves taking a biopsy and its subsequent microscopic examination. Biopsy can be puncture and excisional. The last type of procedure is also therapeutic, when a mole is removed and its subsequenthistological examination. This technique allows you to most accurately establish the diagnosis, but it is used only in the case of superficial nevi.
Therapy
Therapy for skin nevi (ICD code - D22) involves their surgical removal. This can be done for aesthetic or medical reasons. Aesthetic removal is necessary if the mole is a pronounced cosmetic defect.
Today, there are several methods for removing nevi:
- Surgical excision.
- Electrocoagulation.
- Cryosurgery.
- Laser surgery.
The most common way is the latter. The tissues of the formation are evaporated with a carbon dioxide laser, as a result of which the cells in its structure die. The technique is painless, the patient feels only warmth and a slight burning sensation. There are no scars or scars after laser removal. An important role is played by the location of the mole and its size. If it is on the surface, incomplete evaporation may occur, leading to a relapse.
Cryodestruction removes a mole by exposing it to liquid nitrogen. This technique is used if the location of the formation is superficial, and the size is small.
During electrocoagulation, tissue evaporation also occurs, but only with the help of electric current. The method can be used to remove only small moles.
Surgical excision is done with a traditional scalpel. ATDuring the operation, not only the nevus is removed, but also the adjacent tissues. The incision site is then sutured. A similar operation is performed using local anesthesia.
We examined what it is - a skin nevus.
