What is Melanoma (Skin Cancer)?

According to the National Cancer Institute (NCI), in the United States, the number of new cases of melanoma has more than doubled in the past 20 years. Melanoma is a type of skin cancer that begins in certain cells in the skin called melanocytes.

Melanocytes are found throughout the lower part of the epidermis, one of the skin’s two main layers. They produce melanin, the pigment that gives skin its color. Sometimes, clusters of melanocytes and surrounding tissue form benign (noncancerous) growths called moles. Moles can be flat or raised and are usually round or oval and smaller than a pencil eraser. They may be present at birth or may appear later on in life—usually before age 40.

Melanoma occurs when melanocytes become malignant. When melanoma starts in the skin, this is called cutaneous melanoma. Ocular melanoma or intraocular melanoma is when melanoma occurs in the eye.

Melanoma can occur on any skin surface. The disease often develops on the trunk (the area from the shoulders to the hips), the head and neck on men. In women, melanoma is often found on the lower legs. It’s rarely found on black people and others with dark skin. The chance of developing melanoma increases with age, but this disease is one of the most common forms of cancer in young adults.

Types of Melanoma (Skin Cancer)

There are two more common and less serious types of skin cancer, sometimes called nonmelanoma skin cancer. They are:

  • Basal cell carcinoma
  • Squamous cell carcinoma

Risk Factors of Melanoma

These are some of the risk factors associated with melanoma:

  • Family history of melanoma. Having two or more close relatives who have had this disease is a risk factor because melanoma sometimes runs in families.
  • Dysplastic nevi. Dysplastic nevi (or abnormal moles) are more likely in people with fair skin that burns or freckles easily than in people with dark skin. The risk of melanoma is greater for people with a large number of dysplastic nevi. A greater risk exists for people who have a family history of both dysplastic nevi and melanoma. Additional information about moles and dysplastic nevi and melanoma risks is available in the National Cancer Institute (NCI) booklet: What You Need To Know About™ Moles and Dysplastic Nevi.
  • History of melanoma. People who have been treated for melanoma are at a higher risk for developing a second melanoma.
  • Weakened immune system. People whose immune system is weakened by certain cancers, by drugs given following organ transplants, or by AIDS are at an increased risk of developing melanoma.
  • Many ordinary moles. Having more than 50 moles increases the risk of developing melanoma because this disease usually begins in the melanocytes of an existing mole.
  • Ultraviolet (UV) radiation. Experts believe that melanoma is related to an increase in the amount of time people spend in the sun. UV radiation from the sun causes skin damage that can lead to melanoma. There are two types of UV radiation:
    • UVA
    • UVB
    Sunlamps and tanning booths can also cause skin damage and an increased risk of melanoma. To help prevent and reduce your risk of melanoma caused by UV radiation, avoid exposure to the midday sun (from 10 a.m. to 3 p.m.) and wear sunscreen with a high sun protection factor (SPF). You should also wear sunglasses with UV protective lenses. The label should state that the glasses block 99 percent of UVA and UVB radiation.
  • Severe, blistering sunburns. People who have had one or more severe, blistering sunburns as a child or teenager are at increased risk for melanoma. Sunburns in adulthood are also a risk factor for melanoma.

Symptoms of Melanoma

Most of the time, 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. Here’s what you should watch for:

  • Shape. When the shape of one half of a mole doesn’t match the other half
  • Border. Edges around the mole are ragged, notched or irregular – pigment can start to spread into the surrounding skin
  • Color. When the color is uneven and a mole has shades of black, brown, blue, white, tan, gray and/or red
  • Size. Melanomas usually increase in size – usually larger than a pencil eraser (5 mm or 1/4 inch).

Melanoma can be cured if it’s diagnosed and treated early, when the tumor hasn’t deeply invaded the skin. A skin exam is usually part of a routine checkup with the doctor. But, you can also check your own skin for new growth or other changes.The National Cancer Institute (NCI) offers a simple guide called How To Do a Skin Self-Exam to help you examine your skin more regularly.

Diagnosing Melanoma

If your doctor suspects that a spot or a mole on your skin is melanoma, you will need to have a biopsy. In addition, your doctor may order any of the following tests to further diagnose the abnormal area:

Treatment Options for Melanoma

If you’ve been diagnosed with melanoma, your doctor will work with you to develop the best treatment plan to fit your needs. Your doctor may decide to use one treatment method or combination of methods based on the stage of the disease.

Below are the methods most commonly used to treat melanoma.

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