What is Skin Malignant Melanoma?

Risk factors for Melanoma

•       Family history of melanoma
•       Dysplastic nevi
•       History of melanoma
•       Weakened immune system
•       Many ordinary moles (more than 50)
•       Ultraviolet (UV) radiation
•       Severe, blistering sunburns
•       Freckles
•       Fair skin

Type of Skin

Fair skin poses an increased risk because of easy burnig and lack of protection associated with presence of pigment (melanin) into the skin layers.

Personal History of Melanoma

A history of a melanoma harbors a significant risk for developing a second lesion, which may form in up to one quarter of patients, depending also on the presence of other risk factors.

Positive Family History

Approximately one tenth of patients with the malanoma can trace a family member who also had melanoma. The risk is greter if an individual has first-degree relatives affected by melanoma, especially if this occurs under the age of 50, but presence of second-degree relatives is also significant.

Types of Melanoma

Health professionals distinguish four types of melanoma. The most common is superficial spreading melanoma, which is encountered in almost three quarters of cases. This subtype originates “in situ”, meaning that it develops and extends in the most superficial portion of the skin before starting to grow more deeply (“vertical growth”). Commonly the lesion appears as a discolored patch with suspicious features, such as increasing size, irregular borders, or change in color such as black, round, red, blue, or unstained patches. It is more common in young individuals. Because the superficial pattern of growth may last for up to a few years, this lesion can be diagnosed early, before a “vertical growth phase” develops caring the risk of systemic metastases. Acral lentiginous melanoma is a rare subtype, but is frequently encountered in African-American and Asian patients. It also spreads superficially at the beginning. The initial lesion usually occurs as a dark spot on the palms and soles, or under the nails. Lentigo maligna, also a rare subtype, arise from superficial lesions and commonly keeps a non-invasive pattern of spread for a relatively long period of time before producing deep invasion. It tends to originate in sun-damaged skin, mostly on the head and neck, and frequently appears as brown or black lesion, which is flat or slightly prominent relative to the surrounding skin. The deeply penetrating advanced form is known as lentigo maligna melanoma. Nodular melanoma is the only subtype which usually is deeply invasive at the time of presentation. It is considered to be a more aggressive variant, and making the diagnosis can be difficult because of several factors. Some of these lesions do not have any pigmentation (be white or of skin color), and may be located on the scalp. This variant is commonly encountered in elderly people.

People who work or play in the sun should wear protective clothing, such as a hat and long sleeves. Also, lotion, cream, or gel that contains sunscreen can help protect the skin. Many doctors believe sunscreens may help prevent melanoma, especially those that reflect, absorb, and/or scatter both types of ultraviolet radiation. Sunscreens are rated in strength according to a sun protection factor (SPF). The higher the SPF, the more sunburn protection is provided. Sunscreens with an SPF value of 2 to 11 provide minimal protection against sunburns. Sunscreens with an SPF of 12 to 29 provide moderate protection. Those with an SPF of 30 or higher provide high protection against sunburn. It is advisable to wear a sunscreen that protects against both UVA and UVB. Sunglasses that have UV-absorbing lenses should also be worn. The label should specify that the lenses block at least 99 percent of UVA and UVB radiation.

Here is how to do a skin self-exam:

• After a bath or shower, stand in front of a full-length mirror in a well-lighted room. Use a hand-held mirror to look at hard-to-see areas.
• Begin with the face and scalp and work downward, checking the head, neck, shoulders, back, chest, and so on. Be sure to check the front, back, and sides of the arms and legs. Also, check the groin, the palms, the fingernails, the soles of the feet, the toenails, and the area between the toes.
• Be sure to check the hard-to-see areas of the body, such as the scalp and neck. A friend or relative may be able to help inspect these areas. Use a comb or a blow dryer to help move hair so you can see the scalp and neck better.
• Be aware of where your moles are and how they look. By checking your skin regularly, you will become familiar with what your moles look like. Look for any signs of change, particularly a new black mole or a change in outline, shape, size, color (especially a new black area), or feel of an existing mole. Also, note any new, unusual, or “ugly-looking” moles. If your doctor has taken photos of your skin, compare these pictures with the way your skin looks on self-examination.
• Check moles carefully during times of hormone changes, such as adolescence, pregnancy, and menopause. As hormone levels change, moles may change.
• It may be helpful to record the dates of your skin exams and to write notes about the way your skin looks. If you find anything unusual, see your doctor right away. Remember, the earlier a melanoma is found, the better the chance for a cure.

Distinguishing Benign Moles from Melanoma

To prevent melanoma, it is important to examine your skin on a regular basis, and become familiar with moles, and other skin conditions, in order to better identify subtle changes. Any location on the skin can be involved by melanoma, but the sun exposed areas, and in particular the back and legs are frequently affected. Certain areas can be easily missed on inspection, such as the scalp or the back of the ears.

According to recent research, certain moles are at a higher risk for changing into malignant melanoma. Moles that are present at birth, and atypical moles, have a greater chance of becoming malignant. Frequently, melanomas arise as single lesions. Occasionally, one spot may stand out as looking most atypical, and such lesions would be of particular concern.

When used correctly, the sensitivity of these criteria is very high, their role being to indicate that a more thorough evaluation and intervention are needed. Since benign non-cancerous lesions may also contain similar features, it is strongly advisable to promptly consult a medical professional in regard to any suspicious lesion. Although a change in size of a mole is the most frequent change associated with melanoma, all the other signs should be given importance. Although not mentioned in these criteria, occurrence of a bump or “vertical growth phase” over a nevus or a new lesion, and presence of pain associated with a pigmented lesion should also be regarded as red flags for melanoma. Bleeding is often associated with thick lesions, therefore the diagnosis is preferable to be made before the occurrence of this symptom in order to ensure early detection.

The sensitivity of the seven-item tool appears to be even higher than for the ABCDE criteria. Recognition of melanoma is considered to be highest when the exam is conducted by trained dermatologists, but it is not reaching 100%. In order to increase the accuracy of clinical examination and to help distinguish melanoma from other skin entities, a new advance employes the use of dermoscopy. This technique uses an optical magnifying instrument which is applied on the skin and allows better visualization of the structural details through a layer of alcohol or oil immersion. A light source and magnification in the range of 10x allow visualization of details which are not reachable by naked eye inspection. Dermoscopy is becoming increasingly used among dermatologists and results in an increased number of lesions diagnosed early, along with a decrease in the number of surgical biopsies which would be performed because of uncertainties in diagnosis. The sensitivity and the ability to correctly identify melanomas was shown to be improved compared to naked eye examination. Dermoscopy has been successfully applied in patients with dark skin, leading to early and accurate diagnosis of melanoma.

Seeking Medical Advice

Sometimes it is necessary to see a specialist. A dermatologist (skin doctor) have the most training in diseases of the skin. Our doctors at Advanced Dermatology PC are participants of the AAD annual melanoma screening sessions and are often cited in media for their expertise in skin cancer prevention and treatment.

Melanoma may run in families, and members of these families are at high risk for the disease. In some of these families, certain members also have a large number (usually over 100) of dysplastic nevi. These people have an especially high risk of developing melanoma. When two or more family members develop melanoma, it is important for all of the patients’ close relatives (parents, brothers, sisters, and children above the age of 10) to see a doctor and be examined carefully for dysplastic nevi or any signs of melanoma. The doctor can then decide how often each person needs to be seen. (Doctors may recommend that these family members have checkups every 6 months.) Anyone who has a large number of dysplastic nevi also should be examined regularly.

Because most moles, including most dysplastic nevi, do not develop into melanoma, removing all of them is not necessary. In fact, a phenomenon of benign involution if frequently observed in nevi. A doctor can recommend when and when not to remove moles. Usually, only moles that look like melanoma, those that change, or those that are both new and look abnormal need to be removed. Prophylactic removal of benign nevi is therefore not routinely recommended, however this is sometimes considered for cosmetic and psychological reasons.

Suspicious lesions are removed surgically. The removal of the entire mole or a sample of tissue for examination under a microscope is called a biopsy. It is considered preferable to remove the lesion entirely (“excisional biopsy”) with no cancer cells present at the margins of the piece extracted. However, for large lesions or melanomas in difficult anatomic locations a smaller part is removed (“incisional biopsy”). Although not removing the whole lesion from the beginning is not considered to impact the outcome as long as a full resection is done subsequently, very superficial biopsies are not generally recommended because they can potentially miss a deep melanoma.

Analysis of microscopic features of the excised specimens is performed routinely to confirm the diagnosis of melanoma and distinguish from other pigmented lesions that may appear very similar. Although many of these non-melanoma entities are benign, some of them are considered “atypical” or “dysplastic” variants, which place them at increased risk and mandate surgical excision and surveillance.

Stages of Melanoma

After reaching a diagnosis of melanoma, staging or assessment of the extend of the disease is performed in an effort to predict the outcome and the need for other studies and further treatment.

Staging means determining the extent of the disease. More evolved cutaneous lesions have an increased chance to spread to the lymph nodes or to distant sites inside the body. Any organ can become involved with melanoma, but more frequently involved are skin and subcutaneous tissues, lungs, liver, and brain.

Features that determine the staging include the skin tumor thickness, presence of ulceration and microscopic islands surrounding the main tumor, and the presence and number of lymph nodes containing melanoma cells. Only a fraction of patients have melanoma involving regional lymph nodes or distant metastases at diagnosis, which place them in an advanced stage (stages III and IV, respectively).

Stage III

Melanoma is diagnosed when the tumor was found inside the lymph nodes that drain the territory of the melanoma lesion, either as micrometastases (can only be found by examination under the microscope) or macrometastases (can be appreciated by manual palpation during a clinical exam), or other deposits of melanoma are found along the trajectory of lymphatic channels (“in-transit metastases” or “satellites”).

Stage IV

Melanoma consists of distant spread to sites such as lymph nodes, skin, or under the skin (Stage M1a), lungs (Stage M1b), or any other distant organ (Stage M1c).

Once Melanoma Has Been Diagnosed

Assessment of whether the lymph nodes are involved with melanoma is made depending on certain characteristic of the melanoma lesion on the skin. If the nodes are large enough to be found during a physical exam performed by your physician, then a referral will be generally made to a surgeon for a complete surgical extraction of lymph nodes in that territory. If lymph nodes are not detested clinically, but the melanoma has certain high-risk features as assessed by your dermatologist or by a medical oncologist, a specialized surgeon will perform a procedure called “sentinel lymph node biopsy”. This procedure consists of injection of blue dye and a radioactive tracer around the site of the primary skin lesion, after it has been removed. The lymph node uptaking these tracing substances will be located and removed surgically. The advantage of this procedure which now is used routinely is that it produces less risk of postoperative complications (in particular “lymphedema” or chronic swelling of an extremity), while producing similar results as a complete lymphatic removal. If the “sentinel lymph node” is found to be involved with melanoma by looking under the microscope and performing other very sensitive tests, than all the lymph nodes in the region that drain the primary melanoma need to be removed. The best course of action is usually determined for an individual patient by a multidisciplinary team composed of a dermatologist, a medical oncologist, and a surgeon.

Knowledge of the above information and a few simple changes in behavior and lifestyle can prevent skin cancer:

• Wear sun-protective clothing during peak sun hours (10a.m – 2p.m).
• Use sunscreen with both UVA/UVB & physical blocks. Several studies have demonstrated that the use of sun-protective wear and sunscreen can decrease the number of moles and premalignant lesions.
• The American Academy of Dermatology recommends broad-spectrum sunscreen covering both UVA & UVB with a Sun Protection Factor (SPF) of at least 15 or above with reapplication every 2 hours when outdoors, even on cloudy days.
• Make efforts to minimize sun exposure and to apply sunscreen to children aged 6 months and older.
• Clinical trials have demonstrated that sunscreens are effective in reducing the incidence of actinic keratoses and squamous cell carcinomas.
• Another randomized trial demonstrated that, among children who are at high risk for developing melanoma, sunscreens are effective in reducing moles, the precursors and strongest risk factor for melanoma.
• It is strongly recommended to avoid tanning salons due to its possible association with skin cancers.