Skin Cancer-Melanoma

Melanoma at a Glance

• Melanoma is the most serious type of cancer of the skin.
• Melanoma is becoming more common each year in Western countries.
• Risk factors for melanoma include having abnormal moles or having more than 50 ordinary moles, fair skin that burns or freckles easily, personal or family history of melanoma, weakened immune system, severe/blistering sunburns, over exposure to the sun. ultraviolet radiation.
• Signs and Symptoms of melanoma include a change in the size, shape, edges, color, or feel of an existing mole.
• Surgery is the usual treatment for melanoma, sometimes followed by chemotherapy, and if caught early, success rates are high.

What is Melanoma?

Melanoma begins in cells in the skin called melanocytes. Each year in the United States, more than 53,600 people are diagnosed with melanoma.

In some parts of the world, especially among Western countries, melanoma is becoming more common every year. In the United States, the percentage of people who develop melanoma has more than doubled in the past 30 years.

Normal melanocytes are found in the basal layer of the epidermis, i.e. the bottom part of the outer layer of the skin. The melanocytes produce a protein called melanin, which protects the skin by absorbing ultraviolet (UV) radiation. Melanocytes are found in equal numbers in black and in white skin, but the melanocytes in black skin produce much more melanin. People with dark brown or black skin are very much less likely to be damaged by UV radiation than those with white skin. Non-cancerous growth of melanocytes results in moles (properly called benign melanocytic naevi) and freckles (ephelides and lentigines).

Cancerous growth of melanocytes results in melanoma. When melanoma starts in the skin, the disease is called cutaneous melanoma. Melanoma may also occur in the eye (ocular melanoma or intraocular melanoma). Rarely, melanoma may arise in the meninges (membranes that envelope the brain and spinal cord), the digestive tract, lymph nodes, or other areas where melanocytes are found.

When melanoma spreads, cancer cells may show up in nearby lymph nodes. Groups of lymph nodes are found throughout the body. Lymph nodes trap bacteria, cancer cells, or other harmful substances that may be in the lymphatic system. If the cancer has reached the lymph nodes, it may mean that cancer cells have spread to other parts of the body such as the liver, lungs, or brain. In such cases, the cancer cells in the new tumor are still melanoma cells, and the disease is called metastatic melanoma, not liver, lung, or brain cancer.

Risk Factors

Research has shown that people with certain risk factors are more likely than others to develop melanoma. A risk factor is anything that increases a person’s chance of developing a disease. Studies have found the following risk factors for melanoma:

• Dysplastic nevi: Dysplastic nevi are more likely than ordinary moles to become cancerous. Dysplastic nevi are common, and many people have a few of these abnormal moles. The risk of melanoma is greatest for people who have a large number of dysplastic nevi.
• Many (more than 50) ordinary moles: Having many moles increases the risk of developing melanoma.
• Fair skin: Melanoma occurs more frequently in people who have fair skin that burns or freckles easily than in people with dark skin.
• Personal history of melanoma or skin cancer: People who have been treated for melanoma have a high risk of a second melanoma. Some people develop more than two melanomas. People who had one or more of the common skin cancers (basal cell carcinoma or squamous cell carcinoma) are at increased risk of melanoma.
• Family history of melanoma: Melanoma sometimes runs in families. Having two or more close relatives who have had this disease is a risk factor. About 10 percent of all patients with melanoma have a family member with this disease.
• Weakened immune system: People whose immune system is weakened by certain cancers, by drugs given following organ transplantation, or by HIV are at increased risk of developing melanoma.
• Severe, blistering sunburns: People who have had at least one severe, blistering sunburn as a child or teenager are at increased risk of melanoma. Because of this, doctors advise that parents protect children’s skin from the sun. Such protection may reduce the risk of melanoma later in life. Sunburns in adulthood are also a risk factor for melanoma.
• Ultraviolet (UV) radiation: Experts believe that much of the worldwide increase in melanoma is related to an increase in the amount of time people spend in the sun. This disease is also more common in people who live in areas that get large amounts of UV radiation from the sun. Artificial sources of UV radiation, such as sunlamps and tanning booths, also can cause skin damage and increase the risk of melanoma.

Signs and Symptoms

Often, the first sign of melanoma is a change in the size, shape, color, or feel of an existing mole. Most melanomas have a black or blue-black area. Melanoma also may appear as a new mole.

• Asymmetry—the shape of one half does not match the other.
• Border—the edges are often ragged, notched, blurred, or irregular in outline; the pigment may spread into the surrounding skin.
• Color—the color is uneven. Shades of black, brown, and tan may be present. Areas of white, grey, red, pink, or blue also may be seen.
• Diameter—there is a change in size, usually an increase. Melanomas are usually larger than the eraser of a pencil (1/4 inch or 5 millimeters).