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Melanoma

меланома на коже

The melanoma is a type of the malignant new growth which is formed of the melanocytes, cells developing a dark pigment (melanin) under the influence of ultraviolet radiation.

Epidemiology.
The melanoma in human population makes 1% among all types of cancer, and 2,5% of-10% among skin tumors, all are observed 4 cases on 100000 population. The melanoma can develop at any age, but mainly persons have from 30 to 60 years, both at women (more often), and at men. The disease occurs at representatives of negroid race considerably less than at representatives of white race.

Etiology and pathogeny.
Basic reason of development of a melanoma damage of DNA of a cell of a melanocyte under the influence of UF of radiation or other aggressive factors is considered. The following reasons increase risk of development of this malignant tumor:

  • Belonging to a certain phototype (light skin, red or light hair color, blue eyes).
  • Episodes of serious sunblisters, especially at children's age.
  • Constant mechanical traumatization of a nevus.
  •  Systematic impact on birthmarks and birthmarks of chemical irritants (hair-dye, etc.).
  • Existence of a large number of birthmarks.
  • Presence of a nevus (birthmarks, birthmarks) of atypical color and form.
  • Genetic predisposition.
  • Reduced immunity (as a result of a disease of the HIV or administration of drugs suppressing immunity).

Classification.
There are four types of melanomas as distribution and histology:

  • The melanoma of superficial growth – the most often found type of this cancer, makes about 70% of all incidence of melanomas. It is characterized by exclusively epidermal distribution. In a horizontal phase the nevus with initial malignant development looks as formation of irregular shape and color, deckle-edged. In a vertical phase growth appears up, the nevus can ulcerate and become covered by crusts. Women have a localization mainly standing, at men – on a back and a breast, and also in a neck and the head. The forecast, in communication by the long growth of a tumor and detection in an initial stage of development, usually favorable.
  • Nodal (knotty) melanoma – a look, the second for distribution, – 15%. Develops much quicker, than other forms. Localization – in a back, a breast, the head and a neck. The nevus looks as a friable node of bluish-black or dark brown color with a smooth surface. In the course of growth the tumor can become colourless. The forecast adverse because of prompt development of a tumor and the late diagnosis connected with it.
  • Initially pigment-free forms (akrolentigovidny and mucous melanomas). Prevalence – 10%. Small knots of a melanoma have irregular shape, are painted in black color, sometimes happen colourless. Growth is slow. This type of a melanoma is located on the sites which are initially deprived of a pigment. The Akrolentigovidny melanoma is localized on palms of hands and soles of legs, and is characteristic only for persons of negroid and Mongoloid races. Mucous melanomas form on mucous membranes of external genitals, a rectum, on an eyeglobe and so forth. The forecast depends on degree of prevalence of a tumor.
  • Lentigo-melanoma (malignant lentigo) – occurs very seldom, as a rule, at persons of senile age. Arises on sites which many years were exposed to aggressive solar influence, usually on a neck or a face. A precancerous form of a lentigo-melanoma are Hutchison's freckles. The tumor in the form of a small knot of small diameter forms on site freckles for a long time. The forecast is favorable.

Clinic and symptomatology.
The melanoma, in comparison with other types of tumors, creates a very different clinical picture. The melanoma of skin can have various size, the form, color, a surface and consistence. The sizes of a tumor vary from insignificant, in several millimeters, to considerable. In a form the new growth can be correct – oval, round, or any irregular shape. It can take a typical form of papillomatous education, form small protrusion, be located on the flat basis or a leg, to look as a nevus pigmentosus. The surface of melanomas happens as smooth, dense, and friable, at further development the surface ulcerates, there is bleeding at any contact. In the last stage of development the tumoral node breaks up and reminds a cauliflower.
About a half of melanomas arises on site already existing birthmarks, freckles or birthmarks. Other half forms on site smooth skin and arises as a nevus pigmentosus or a site of skin with unusual structure. The check diagnostic list which gives an idea what it is necessary to pay attention to was developed for differentiation of a malignizirovanny tumor from a usual nevus:
- existence of asymmetry or abnormality of a form allow to suspect a nevus ozlokachestvleniye, the usual birthmark has the symmetric form;
- unlike a birthmark with constant and certain borders, the melanoma has irregular and uneven edges;
- melanomas, as a rule, have more than one color in the borders. They can have different shades: brown with black, red, pink, white or bluish. The healthy birthmark usually has a homogeneous shade of brown color;
- it is necessary to pay attention to diameter of skin education, the usual birthmark, as a rule, does not exceed the pencil tip sizes (about 6 mm in the diameter);
- it is necessary to watch any changes of the size, a form or color of a birthmark which are birthmark malignancy signs.
Existence of any of above-mentioned symptoms is a reason for the address to the doctor.
Signs of development of a melanoma can be also expressed in an itch and a pricking in the field of a birthmark, in its bleeding.

Diagnosis.
It is quite easy to make the diagnosis of a new growth of skin on the basis of poll of the patient and his survey. It is necessary to make additional cytomorphological researches for exact identification of species of a tumor and its features.
The most important point when diagnosing a tumor is establishment of degree of its prevalence and a stage of development. According to the international standards the system of a stadirovaniye (TNM) which includes researches on three parameters is used:

  • T designates tumor. Determination of thickness of a melanoma (using Beslou's method) and degrees of its izjyazvlennost. Thickness of a melanoma is the depth of distribution (invasion) of a tumor from a skin surface, is measured in millimeters. Thin melanomas (less than 1 mm) have every chance of fast and full healing. The ulceration of a new growth shows a stage of its development.
  •  The indicator of N establishes as far as the tumor took lymphatic system.
  • Parameter M defines whether there are metastasises in other bodies and systems.

Treatment.
The choice of a method of treatment of a melanoma is based on diagnostic materials and considers, first of all, a stage of a tumor and feature of its development.
At rather superficial invasion (a stage 1 and 2) surgical methods of treatment are applied. The tumoral center is excised an electroknife with capture of healthy fabric at the edges and removal of hypodermic cellulose. At localization of a melanoma on skin of fingers their amputation is shown. At the 2nd stage of a melanoma in 2-3 weeks after the first operation make removal of all nearby lymph nodes (sentry). At treatment 3 stages before operation apply a method of a short-distance roentgenotherapy (radiation therapy). After surgical intervention carrying out chemotherapy for 4-6 months in combination with an immunotherapy is shown. Treatment 4 stages owing to prevalence of metastasises on all organism is not productive and is carried out for the purpose of reduction of symptomatology and improvement of quality of life of the patient.
Survival degree after the carried-out treatment during 10 flyings makes at the 1st stage – more than 80%, at the 2nd stage – more than 55% and above, at the 3rd stage – about 25%, at the 4th – about 10%.

Prevention.
As until the end of an origin of a melanoma are not studied, it is possible to make only the general recommendations about prevention of this disease. First of all, they include continuous supervision over a condition of birthmarks and birthmarks. It is also necessary to avoid all situations, stressful for integuments: not to sunbathe long, to use sun-protection means, not to subject a nevus to chemical and mechanical influence, etc.

 
"Valdenstrem's macroglobulinemia   Metastasises of cancer of unknown primary localization"