2. Etiology and pathogenesis of keratoacanthoma
3. Signs and symptoms
4. Diagnostics keratoacanthoma
5. keratoakantom Treatment
Keratoacanthoma - a rapidly developing benign epidermal tumors of hair follicles.As a rule, this formation occurs on the extremities and exposed parts of the body, mostly on the extensor surfaces.
keratoacanthoma In some cases can occur on the mucous membranes of the lips, cheeks, palate, under the nails, and mucosal surfaces of the nose.The elderly are most susceptible to this disease.In addition, men suffering from this disease is about twice as often as women.
skin keratoacanthoma divided into several forms, among which are distinguished the gigantic form, solitary, subungual, plural form combined with the syndrome Torre or immunosuppression, multiple eruptive form (multiple samozazhivayuschie skin keratoacanthoma in children and adolescents), as well as the form of the diseasea circumf
To date, accurate information about the etiology of the disease is not established.It is noted that a direct role in the development of viral factor plays a keratoacanthoma.Nearly half of patients with solitary form of the disease found viral particles at the ultrastructural level, as well as the DNA of human papilloma virus type 25.Generalised skin keratoacanthomas in most cases is hereditary.In this case, the disease is transmitted in an autosomal dominant manner.
Multiple keratoacanthomas often occurs against a background of tumors of internal organs, especially the digestive tract, as well as paraneoplazii.It is also found that the formation of skin keratoacanthoma can be based on the development of hyperplastic epithelium funnel of one or more hair follicles and associated sebaceous glands.
Keratoacanthoma is a round or oval exophytic node on a broad basis, acquire, usually reddish or bluish tinge.The size of education is on average 2-3 cm in diameter.In the central part of the tumor mass located horny but raised edge zone in the form of a high roller.
Typically, after a phase of rapid growth of the tumor stabilization phase begins, during which education does not change its shape and size.After about 6-9 months, the phase of spontaneous regression, during which the tumor site disappears completely, leaving an atrophic scar.It should be noted that in some cases the stabilization phase does not occur, whereby the assembly can achieve huge size (10-20 cm in diameter).Multiple
keratoacanthomas occurs, usually in the form of successively occurring units or a small number of lesions appearing at one time.In the first case, the elements gradually emerge in different parts of the skin, mostly on the legs and face.These formations represent papules and nodes with depressions in the central part filled with horny masses that are resolved within a few months, after which the place of their education remain atrophic scars.The second variant of the disease suggests the emergence of a large follicular papules measuring 2-3 cm in diameter.
Diagnosis of the disease is based on clinical manifestations.When solitary and multiple formations excisional biopsy is performed, while in the event of major elements prescribed diagnostic biopsy roller zone.Based on the results of pathological studies are three main stages of keratoacanthoma.
The first step (step A) is characterized by a recess in the epidermis, which is filled with horny masses.On the sides are surrounded by a horny mass duplikatury epidermis.Epidermal cords away from the base of keratotic plugs into the underlying dermis.However, they contain cells with hyperchromatic nuclei.It should be noted that the basement membrane zone remains intact.
second stage of the disease (stage B) is characterized by identifying the base of the crater pronounced epithelial hyperplasia with penetration into the dermis ploskoepitelialnyh strands.
cells sprout layer reach large size, pale colored.In some cases, they viewed the phenomenon of mitosis and dyskeratosis.Signs of cell atypia and polymorphism observed in epidermal outgrowths.Edema and inflammatory reaction with lymphocytes polymorphic type, eosinophilic, neutrophilic granulocytes with a dash plazmotsidov observed in the dermis.In some cases, the fall in the cell infiltrate epidermal outgrowths.Sometimes, a similar picture is considered as a precancerous condition.
third stage (stage C) is characterized by the violation of the basement membrane integrity with the development of epidermal outgrowths deep into the dermis, as well as complexes otshnurovkoy ploskoepitelialnyh cells.Marked increase in polymorphism and giperhromatoz nuclei.Abnormal cornification to form a "horn pearls" replaces dyskeratosis.Dense inflammatory infiltrate is detected at the base of the hearth.
Regression usually occurs on the first or second stage of the disease.This decreases the horn tube, normal structure of the basal layer of the epidermis proliferation stops.Quite a number of fibroblasts with subsequent fibroplasia and scar formation is formed in the infiltrate.
Histological changes in multiple keratoacanthoma match solitary form.However, when the plural form of the disease proliferation and atypia are less pronounced, and communicate with the epithelium of the mouth of the hair follicles can be traced quite clearly.
Treatment of solitary small elements based on the surgical section elektroissechenii, laser vaporization, cryoablation.
Surgery-section is used, as a rule, when large solitary cell.
Therapy synthetic retinoids is carried out at multiple foci, as well as the prevention of malignancy formations.
Keratoacanthoma is a neoplasm characterized by rapid development and, in some cases, spontaneous regression (usually 2-6 months).In some cases, skin keratoacanthomas can transform into squamous cell carcinoma.
This article is available exclusively in the educational purposes and is not research material or professional medical advice.
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