What is Melanoma?
Melanoma is a cancer that begins in the melanocytes, a certain type of skin cell. Because most melanoma cells still make melanin, melanoma tumors are often brown or black in color. Some melanomas do not make melanin and can appear pink, tan or even white.
Melanoma can occur anywhere on the skin, but they are more likely to start in certain locations. The trunk (chest and back) is the most common site in men. The legs are the most common site in women.The neck and face are other common sites.
Having a darker skin tone lowers your risk of melanoma at these more common sites, but anyone can develop melanoma on the palms of the hands, soles of the feet, and under the nails. Melanomas in these areas account for more than half of the cases in African Americans but fewer than 1 in 10 melanomas in Caucasians.
Melanomas can also form in other parts of your body including the eyes, mouth, genitals and anal area but these are much less common than melanoma of the skin.
Melanoma is much less common than basal cell and squamous cell carcinomas, but it is far more dangerous. Like basal cell and squamous cell cancers, melanoma is almost always curable in its early stages. But it is much more likely than basal or squamous cell cancer to spread to other parts of the body if not diagnosed and treated early.
Main types of melanoma
Superficial spreading melanoma accounts for 70% of melanomas. Typically asymptomatic, it occurs most often on women’s legs and men’s torsos. These lesions are usually irregular and raised with tan or brown areas. They sometimes have red, white, black, and blue spots or small blue-black nodules. Small indentations in the margins may be visible along with color change.
Nodular melanoma accounts for 15 to 30% of melanomas. Nodular melanoma may occur anywhere on the body as a dark, bulging papule that varies from pearl to gray or black. Some lesions contain little if any pigment or may look like a vascular tumor. They are typically firm and may grow rapidly. Unless it ulcerates, nodular melanoma is often asymptomatic.
Lentigo maligna melanoma accounts for 5% of melanomas. It usually occurs on the face or other areas of chronic sun exposure. Typically, Lentigo Melanoma is a flat, tan or brown, irregularly shaped patch. It may have darker brown or black spots scattered irregularly on its surface.
Acral-lentiginous melanoma accounts for only 2 to 10% of melanomas. Although Acral-lentiginous melanoma is rare in people with lighter skin types, it is the most common type of melanoma in people with darker skin. Acral-lentiginous melanoma is observed on the palms of the hands, soles of the feet, under the nails and in the oral mucosa. It occurs on non hair-bearing surfaces of the body which may or may not be exposed to sunlight. It is also found on mucous membranes. It may appear as a longitudinal tan, black, or brown streak on the nail of a finger or toe.
Melanoma Statistics in the United States
For more information about clinical trials for melanoma please visit the National Cancer Institute.
For information about a clinical trial through Harvard University click here.
Other Skin Cancers
Skin cancers that are not melanomas are sometimes grouped as non-melanoma skin cancers because they develop from skin cells other than melanocytes. They tend to behave very differently from melanomas and are often treated in different ways.
Most non-melanoma skin cancers are basal cell or squamous cell cancers. They are by far the most common skin cancers, and actually are more common than any other form of cancer. Because they rarely spread (metastasize) to other parts of the body, basal cell and squamous cell skin cancers are usually less concerning and are treated differently than melanoma.
Skin Cancer Statistics in the United States
More than 3.5 million cases of non-melanoma are diagnosed in the United States each year.
It is estimated that one in five Americans will develop skin cancer in their life time.
The annual cost of treating skin cancers in the U.S. is estimated at $8.1 billion. This includes $4.8 for non-melanoma skin cancers and $3.3 billion for melanoma.
American Cancer Society
World Health Organization
Early Detection can be a Matter of Life and Death
Know your skin: It is important to note any changes to your skin. Use the following as a general guide when performing monthly self-skin exams.
A: Asymmetry. If you were to divide the mole in half vertically would it be the same on both sides? What if you divide it in half horizontally, or diagonally? You want your moles to be the same no matter which way you divide it in half.
B: Border. What does the border of your mole look like? Is it smooth? Is it irregular, blurred or poorly defined? The border of your moles should be smooth, well defined and even.
C: Color. Moles can come in a variety of different colors black, white, red, brown and even blue. What you’re looking for here is that your mole is the same color throughout. You want to make sure your mole does not have different shades of the same color or completely different colors from one area to the next.
D: Diameter. How big is your mole? Melanoma can be in any sized mole but most healthy moles do not exceed the size of a pencil eraser, about ¼ of an inch, 6 millimeters. If your mole if bigger it should be examined by a dermatologist.
E: Evolving. Has your mole been changing over time? The best tip here is to take a picture of it every month so you can compare each time you do a self-exam. You are looking for any difference here—color, shape or size.
If you find a mole that does not pass one or more of the ABCDEs of melanoma see a dermatologist. Also see a dermatologist if you have a mole that itches or bleeds or if you find a nodule under your skin. It is better to get a mole you are unsure about checked just to be safe.
Sun Safety Tips
Please keep in mind that the ABCDE rule is only a guideline. Melanoma also may appear as a nodule under the skin. Take note of any new marks or moles on the skin and any changes in existing marks or moles. See a dermatologist annually for a full-body skin examination.