Nevus
The content of the article:
- Causes
- Classification
- Types of nevi and their symptoms
- Diagnostics
- Treatment
- Prevention of melanoma formation
- Video
A nevus (birthmark or age spot, birthmark) is a pigmented neoplasm on the skin that is benign.
Moles are not visible on the body of newborn children; they begin to appear somewhat later. They are found in 4-10% of infants, and after puberty, they are found in almost 90% of people. With age, the number of nevi decreases. So, people aged 20-25 have an average of 40 moles, and by the age of 80 they often do not have a single one.
The vast majority of people have nevi
Causes
Pigmented spots can form for reasons of congenital and acquired nature.
Congenital nevi are a malformation of embryonic development. Their occurrence is caused by a violation of the process of moving from the neuroectodermal tube into the skin of precursor cells of melanocytes (melanoblasts). The accumulation of these cells in the skin and causes the appearance of a pigment spot.
Acquired age spots are formed under the influence of the following factors:
- significant changes in hormonal levels (puberty, pregnancy);
- skin infections;
- excessive insolation of the skin.
Classification
Depending on the size, nevi are divided into several types:
- small - diameter no more than 1.5 cm;
- medium - from 1.6 to 10 cm;
- large - over 10 cm.
If a birthmark occupies a large part of the anatomical area, then it is called a giant one. Giant forms of neoplasm are often localized on the face or back.
At the site of localization in the thickness of the skin, the following types of nevi are distinguished:
- borderline or mixed - the accumulation of melanocytes is located at the border of the dermis and epidermis;
- epidermal - an accumulation of melanocytes are located in the upper layer of the skin (epidermis);
- intradermal - an accumulation of melanocytes is localized deep in the dermis.
Types of nevi and their symptoms
Depending on the characteristics of the clinical picture, age spots are divided into several types, presented in the table:
| View | Symptoms |
| Blue (blue, Jadassona - Tiche) | It got its name for its characteristic dark blue surface color. Usually it is single, but sometimes multiple age spots can be observed. Refers to benign tumors, but under the influence of unfavorable factors, it can undergo malignancy and turn into melanoma. |
| Borderline | It looks like a small spot of black, gray or brown color, with a diameter of 2-3 mm to 4-6 cm, but often not more than 1 cm. The surface of the formation is dry and smooth, slightly uneven. She lacks even vellus hair. It can appear on absolutely any part of the human body. There is a risk of degeneration into a malignant tumor. |
| Nevus Ota | It looks like a single spot or a group of merging spots of dark blue irregular shape. Located in the upper jaw, cheeks, paraorbital region. Pigmentation often spreads to the mucous membranes of the oral and nasal cavity, pharynx, sclera of the eyes. The disease is one-sided. It poses a certain danger in terms of malignancy. |
| Complex pigmented | Brown pigmentation associated with the accumulation of melanin in the dermis and epidermis simultaneously. It looks like a round wart or papule with a diameter of no more than 1 cm. There is a high probability of its transformation into melanoma. |
| Verrucous | It is a warty growth of a dark color, towering above the surface of the skin. The surface is bumpy, reminiscent of cauliflower. Refers to melanomone-dangerous forms of the disease. |
| Papillomatous |
It looks like a bumpy mole, resembling a papilloma and protruding above the skin surface. Most often localized in the scalp. |
| Setton's nevus (halonevus) | The pigment spot on the periphery is surrounded by a small area of skin devoid of melanin. Formations are single and multiple. It is prone to independent regression, but in some cases it is complicated by the development of melanoma. |
| Dysplastic | It looks like a small mole with jagged borders. The surface is colored unevenly brown or black. It can be located on any part of the body and head. Very often malignant. |
| Giant pigment | The spot is significant (over 20 cm in diameter) and often occupies entire anatomical areas. Subjected to degeneration into a malignant tumor. |
| Fibroepithelial | Melanomone-dangerous benign neoplasm on the leg, reaching a diameter of 1.5 cm. It has a soft consistency. Flesh to dark brown in color. |
| Sebaceous gland nevus |
The tumor is formed by altered hair follicles and hyperplastic sebaceous glands. The typical location is the head. It looks like a yellowish-pink plaque with an oval, linear or irregular shape and a warty surface. |
You can see what this or that type of age spots looks like in the photo in special atlases of dermatological diseases.
Diagnostics
Patients with suspicious age spots should be registered with a dermatologist. At the initial visit, the doctor examines the neoplasm, specifying its shape, color, size and other visible characteristics. In addition, he conducts a survey of the patient, finding out the following points:
- when the age spot appeared;
- whether its shape, color and / or size has changed recently;
- what caused the changes (attempted removal, scratching, burns, skin infection, trauma).
To clarify the diagnosis and determine the benign or malignant neoplasm, special diagnostic methods are required.
Currently used in the diagnosis of age spots:
- Cytological examination. If there are cracks or bleeding on the surface of the lesion, the doctor may take a smear and examine it under a microscope. The result is usually ready the next day.
- Histological examination. It is performed in the conditions of an oncological dispensary. Under local anesthesia, complete removal of the formation is carried out with the obligatory excision of the surrounding healthy tissues by about 5-6 mm. The wound is sutured with subcutaneous or regular skin sutures. The resulting tissue is sent for histological examination. If malignant cells are found in it, the patient is prescribed radiation and / or chemotherapy.
- Epiluminescence microscopy. Vital examination of tissues using a special optical device - a dermatoscope.
- Computer diagnostics. Using a high-resolution digital camera, a photo of the pigment spot is taken. The resulting image is then processed by a computer program.
Treatment
Melanoma-free age spots can be removed in one of the following ways:
- cryodestruction;
- electrocoagulation;
- laser radiation;
- radio knife.
With a high risk of degeneration of the pigment spot into melanoma, only surgical removal is indicated, with the obligatory excision of the surrounding healthy tissues.
In some cases, only a specialist can distinguish a melanoma-prone mole from a harmless one.
Prevention of melanoma formation
In all countries of the world, there is currently a steady increase in skin melanoma. This malignant tumor is characterized by rapid growth and metastasis to the brain, liver, and lungs. Mortality with it reaches 50%.
According to statistics, the development of melanoma in most cases is preceded by certain types of nevus. Therefore, patients with such skin formations should observe the following preventive measures:
- try not to be in the open sun during the daytime (for central Russia from 11 to 17 hours), when the intensity of solar radiation is maximum;
- use sunscreen;
- refuse to visit the solarium;
- carefully observe the existing and newly appeared age spots.
Patients should be informed that when new pigmented skin lesions appear, as well as changes in the characteristics of existing ones (shape, size, color), they need to consult a dermatologist or oncologist as soon as possible.
Video
We offer for viewing a video on the topic of the article.
Elena Minkina Doctor anesthesiologist-resuscitator About the author
Education: graduated from the Tashkent State Medical Institute, specializing in general medicine in 1991. Repeatedly passed refresher courses.
Work experience: anesthesiologist-resuscitator of the city maternity complex, resuscitator of the hemodialysis department.
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
