What is it?
Melanoma (ex nævocarcinome) is a malignant tumor developed from melanocytes.
Melanocytes are found in the skin, mucous membranes, eyes and central nervous system.
The incidence of melanoma is increasing in the world.
Causes and risk factors
The causes are unknown, but risk factors have been identified.
The disease affects many more subjects skinned.
The importance of phototype is demonstrated by the exceptional nature of malignant melanoma in people with black skin. Conversely, in people of Caucasian, inability to tan and tendency to sunburn, blue eyes, blond hair or red, the complexion clear, the presence of Ephelides (freckles) are factors known risk.
The risk of melanoma decreases when the degree of pigmentation increases.
Sun exposure is a risk factor, especially as it was intense and took place within the first 15 years of life.
Solar explosions are followed by peaks in frequency of melanoma.
There is a hereditary factor.
In some cases, these hereditary factors are important: family and malignant melanoma-BK Mole Syndrome.
Malignant melanoma families are defined by two or more melanomas in one family. They represent 1 to 6% of all melanomas.
The BK-Mole syndrome (B and K are the initials of the surnames of the first two patients in the individualized syndrome; Mole means naevus in English) is the association in several members of a family of malignant melanoma and dysplastic nevi.
The dysplastic nevi are nevi individuals by their clinical appearance and histology. This syndrome is inherited autosomal dominant with high penetrance. It represents 95% of cases of familial melanoma.
The subjects with dysplastic nevi under the BK Mole Syndrome have a high risk of developing malignant melanoma. History of malignant melanoma outside the familial BK Mole Syndrome represent a risk factor.
Most malignant melanomas are spontaneous, and there are only 20 to 40% arising from a pigmented nevus.
The degeneration of a nevus is rare. It should be suspected if the degeneration naevus:
* A changed color, became polychromed with extension of the pigmentation on the skin;
* A grossi stood, was souvert of scales or crust;
* Ulcerate or bleed;
* Gratte.
The number and size of nevi (diameter greater than 2 cm) are a marker of risk but these nevi are not precursors of melanoma mandatory.
The melanoma (lentigo maligna or LMM: lentigo malignant melanoma)
That is the least serious form affecting the elderly.
The melanoma appears on the face or other skin area exposed to the sun. This is a great spot without functional sign, 2 to 6 cm, flat, brown or color hale, with dots of darker pigmentation, brown or black irregularly arranged on its surface.
Pigmented a closet, often in the face, gradually expanding. Malignancy is purely local. After ten years, a nodule may be invasive.
The complete excision is an effective treatment ..
The extension to superficial melanoma (malignant melanoma superficial or extensive SSM = Superficial Spreading Melanoma)
It appears at any age after puberty, often between 30 and 50 years.
He sits generally on the back in humans, on the leg in women.
Initially, it is a small stain brown or black pigment 5 to 10 mm in diameter, asymmetrical, irregular. Beyond 10 mm appear beaches blue, gray or pink pigmented areas and carrying out the characteristic of an injury to polychromed irregular pattern of geography.
This dark brown spot is often confused at the beginning with a benign pigmented naevus but some signs should worry:
* Transformation recent extension or noticed by the patient;
* Changing size, color, appearance, consistency, shape;
* Irregular edges;
* Polychromy of the lesion
Less sinking melanoma in the dermis, it is less dense, the better the prognosis, so the concept of local initial malignancy.
The tumor thickness determines the Breslow index:
prognostic indicator is the most important. It is an objective and reproducible method which measure vertical ocular micrometer thickness from the epidermal granular cell tumor to the deepest.
Nodular melanoma
It is a more severe form.
It is characterized by a vertical progression of the tumor is more aggressive than other types of melanoma. The prognosis is unfavorable because the thickness of the lesion is already high.
It occurs at any age (20-60 years) on a pre-existing moles or skin healthy. It forms a black knot of rapid growth, quickly becoming a burgeoning and bleeding. The usual reason for concern is a rapid extension of papules protuberance, or a dark plate. The color varies from gray to black pearl.
[?] Reviews and analyzes
The exeresis of lesions suspected to be melanoma is required for histological examination.
In case of confirmation, a balance sheet expansion is undertaken:
* Research of the lymph nodes;
* Radiography of the lungs;
* Scanner cérébral;
* Liver scintigraphy.
Metastases occur through blood and lymph.
Differential Diagnosis
Many injuries colored by the pigment melanin pigment or blood can be mistaken for malignant melanoma.
But the recent increase, bleeding, ulceration, or the appearance of a darker hue are indications to the surgery or biopsy of pigmented lesions.
Early diagnosis is possible if the biopsies are performed on lesions with:
* Colorful colors (brown or black with hints of red, white or blue);
* The irregular relief palpable or visible;
* Limits irregular with indentations and notches.
Prevention is based on the promotion of early detection, particularly justified and effective in melanoma.
Treatment
The surgical excision of the initial injuries is needed.
The only way to deal effectively and obtain optimal prediction is early detection of the tumor by inspection and practice a biopsy to evaluate histologically the thickness.
Prevention and screening
The risk factor most famous of malignant melanoma is exposure to ultraviolet radiation, including intense and repeated for short periods. The role of exposure in childhood has recently been emphasized. The prevention is to avoid sun exposure to the hottest hours of the day, to protect the skin by covering clothing and / or creams antisolaire sunscreen. These tips are primarily directed to issues skinned little or no tanning, especially if they are carriers of multiple nevi or dysplastic nevi syndrome.
Early detection of malignant melanoma for the treatment of tumors at a stage where they are curable.
The clinical and photographic subjects at risk is recommended.
The prevention of melanoma requires the limitation of pollution that could reduce atmospheric photoprotection, informing people about the risks of solar radiation, a well-understood individual photoprotection adapted to each phototype, and screening individuals at high risk of melanoma.
* A brown or black stain on the skin changes (in size, form, color, contour) in a few weeks or months, outside of childhood, is a quick reference;
* No one is better placed than himself or his family to monitor her skin;
* Remove a mole suspect is a simple, safe, remove it too late to sign the death warrant;
* If a family member presented a melanoma, or if the subject is carrying a large number of moles dishes, a larger diameter pencil, it is predisposed to develop melanoma;
* The greater the number of moles, the higher the complexion and hair are clear, the risk of developing melanoma is high. This risk is even clearer that the sun was important