Malignant melanoma is one of three major forms of skin cancer. Malignant melanoma develops from cells located primarily in the skin, called melanocytes. These cells produce the pigment melanin, which provides the skin with its typical brownish tone. A mole, or a ‘beauty spot', is an example of a cluster of normal melanocytes localized in one spot.

Malignant melanoma is a cancer which usually develops in the skin, but can also develop in other locations in the body which contain melanocytes, such as the eye or the mucous membranes.

Contrary to the other two common forms of skin cancer, basal cell carcinoma and squamous cell carcinoma, whereby excising the tumor actually heals the patient, the life expectancy after the excision of a melanoma lesion depends on the thickness of the growth, measured in millimeters. For instance, over 95% of the patients with superficial melanoma, less than 1 millimeter in thickness, are cured by a simple, appropriate surgical excision of the tumor. However, in patients with thicker melanomas, there is an actual risk for recurrence, which could reach 40%, if the thickness of the melanoma exceeds 4 millimeters. This is because thicker melanomas have already spread by the time of diagnosis, yet the centers of spread are microscopic and are not detectable by the currently existing imaging methodologies. One way to assess whether a melanoma has already metastasized is to biopsy the regional lymph nodes which drain the region of the melanoma, and examine the tissue under the microscope. This procedure is known as a biopsy of the ‘Sentinel Nodes'.     

It is important to point out that the majority of patients with skin melanoma are cured by the surgery. Hence the importance of monitoring and early detection in the primary stages of any suspicious mole. Only a minority of the patients will suffer a recurrence of the disease over time. Such a recurrence requires advanced and complex treatment modalities, aimed at reinforcing the patient's immune system.

Risk Factors

Which populations are at risk, and what are the significant risk factors for developing melanoma?

Several risk factors are known, most prominent of which are:

·        Many moles, and in particular, a-typical moles.

·        Personal or family history of melanoma.

·        Pigment afflictions from birth.

·        Light skin, light or red hair.

·        Extensive sun burns (particularly during childhood) and intense exposure to sun radiation (particularly intermittent exposure).

Melanoma is, therefore, a malignant growth of the skin. The reasons for the development of melanoma are diverse, and focus on two primary causes: 

Environmental causes - sun radiation, and genetic causes - skin structure, existence of multiple pigment afflictions, etc. These two primary causes ultimately diverge and cause genetic changes (mutations) in the melanocytes, which enable the malignant transformation to melanoma.

As in all other malignancies, the best and most efficient way to combat melanoma is by prevention, by means of handling the most prominent risk factors:  by education and monitoring of populations found at high risk to develop melanoma, and by avoiding excessive exposure to sun radiation.

When outside, it is recommend to cover the body as thoroughly as possible, wearing long pants and long-sleeved shirts, preferably from tightly woven fabrics. It is recommended to wear a broad-rimmed hat and sunglasses which filter the passage of the sun's rays. Sun screens with a Sun Protection Factor (SPF) exceeding 15 should be applied to all exposed areas. Staying outside or at the beach between 9 AM and 5 PM should be avoided.

Application of a sun screen intended for tanning is dangerous, and could increase the risk for melanoma, since it prolongs the exposure to the sun. Epidemiological studies in Europe demonstrated that exposure to the sun for tanning was longer, as the SPF of the sun screen was higher.  

Early Detection

As early as possible diagnosis of melanoma provides the highest chance for a complete cure.

As stated before, most patients with superficial melanoma less than 1 millimeter in thickness are completely cured by a simple surgical excision of the tumor. However, when melanoma is diagnosed at an advanced stage, when it is thick, there is a risk of spreading and the development of a metastatic disease, which is most dangerous and could be lethal. These reasons illustrate the great importance of early detection.

Early detection of melanoma can be achieved by educating the population to be aware of early signs of melanoma development, and by a professional monitoring, especially of high risk populations.

The clinical signs of the development of malignant skin melanoma include:

·        Appearance of a new pigment affliction on a skin area which was previously normal.

·        Changes of an existing mole (usually minor changes), according to the ABCD rule, which include:

Asymmetric shape

Changes in the Borders

Changes of the Color and tone

Changes in the Diameter

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