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Fibroepithelial nevus
Last reviewed: 27.11.2021
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Among the large number of various hypertrophic skin changes, dermatologists distinguish fibroepithelial nevus - a common type of pigmented convex moles.
Epidemiology
According to some reports, in women, fibroepithelial nevi appear twice as often as in men; the peak of their development falls on the age of 40-60 years. [1]
In at least 20% of cases of removal of such moles, their relapse is noted.
Causes fibroepithelial nevus
Fibroepithelial nevi - are formed on the surface of the skin (epidermis) sporadically and belong to benign moles , which experts consider melanomone-dangerous formations, that is, not leading to the development of skin cancer - melanoma.
When listing the likely causes of the appearance of moles , dermatologists name both developmental anomalies (often caused by genetic factors) and hormonal changes, as well as exogenous risk factors for the appearance of pigmented fibroepithelial nevi on the skin.
Among such factors is ultraviolet radiation (as you know, excessive UV radiation has a mutagenic effect on the skin), although research data on the dose-dependent effect of exposure to sunlight on the appearance of nevi are contradictory. [2]
In addition, risk factors include ionizing radiation (or increased background radiation) and skin injuries (primarily chemical), seborrheic keratosis. [3]
Of the most scientifically substantiated versions, only deviations in the development of the skin during the embryonic period can be distinguished, which, in turn, does not exclude their connection with certain pathologies of pregnancy or teratogenic effects. [4]
Pathogenesis
The mechanism of development of nevi, including fibroepithelial nevi, the researchers have not fully figured out, but the fact that it is associated with skin embryogenesis is beyond doubt.
That is why some experts attribute these nodular formations to tissue defects - hamartomas.
In particular, pathogenesis is considered as a result of certain abnormalities in the migration of the initial cells of the embryonic neural crest to ectodermal areas (primarily to the skin and central nervous system) and their transformation into skin melanocytes, which are special cells of the basal stratum that produce pigments (dark eumelanin and light pheomelanin) that protect the skin of the body from UV radiation.
Probably, in the process of intrauterine histogenesis, for some reason, connective tissue cells that make up the fibrous fibers of the underlying dermis (the lowest layer of the skin) can also penetrate through the basement membrane into the epidermis. Or, which also fits well into this version, the protoplasmic processes of the basement membrane, which are formed in the skin structure in the early period of intrauterine development and have reticular fibers, locally change direction - towards the epidermis.
In cases of acquired nevi, an unknown signal is thought to trigger the proliferation of melanocytes. [5]
Symptoms fibroepithelial nevus
It is difficult to distinguish the symptoms of asymptomatic convex fibroepithelial nevi on the skin. Such moles are divided into congenital and acquired, but in both cases, these formations on the skin of the trunk or face have a clearly limited rounded shape and a wide base (leg); maximum diameter - 10-12 mm; their surface is most often smooth (with the usual skin pattern), but it can also be bumpy.
Many have hairs growing from the body of a mole. Such nevi are elastic to the touch, and their color options range from flesh to pinkish and all shades of brown. Such nevi do not cause any sensations. [6]
Complications and consequences
As already noted, the fibroepithelial nevus does not transform into a melonoma, however, it can be damaged, which causes bleeding and does not exclude the development of inflammation.
But after its removal, complications are possible, in more detail in the material - Consequences of removing a mole .
Diagnostics fibroepithelial nevus
First of all, dermatologists examine the nevus and perform dermatoscopy . [7] All details are in the publication Diagnostics of moles .
Differential diagnosis
Differential diagnostics should be carried out with such formations on the skin as dermatofibroma or basalioma, as well as with other types of moles on the body .
Who to contact?
Treatment fibroepithelial nevus
There is no medical treatment for nevi, and surgical treatment involves their removal (most often for cosmetic reasons) using electrocoagulation, laser, radio waves, and scalpel excision. All the necessary information in the material - Removal of moles: an overview of the main methods .
But only the usual surgical excision allows you to conduct a histology of the mole after its removal and make sure that the nevus is benign.
Prevention
To date, there are no specific measures to prevent the occurrence of fibroepithelial and other nevi.