Overview: What You Need to Know

Melanoma is a common but serious skin cancer which, if not removed early while it is thin, may spread quickly and become fatal. It is often ignored until too late because, in the early stages, it may look harmless and cause no discomfort. Many people don’t realize that something small on their skin can be lethal if not treated promptly.

Although it is uncommon in children under 10, melanoma occurs in every age group after puberty. It is the most common cancer in the 25 to 29 age group and second only to breast cancer in women ages 20 to 39. Overall, melanoma is the fifth most common cancer in males and sixth in females. The US incidence of melanoma is nearly five times greater than new HIV/AIDS infections and is increasing rapidly; 200,340 new cases are predicted for 2024. Only 10% of new melanoma patients have a family history of the disease; it can strike anyone regardless of health, physical condition, or skin complexion. On the average, there is a melanoma death in the US every 56 minutes.

The good news is that melanoma is easy to detect yourself at an early stage while it is thin and is curable by simple, painless removal in an outpatient setting. All it takes is a ten-minute monthly skin check. Our melanoma education shows you how to check your skin, what to look for, and how to decrease your risk of developing melanoma in the future.

How Does Melanoma Start?

Melanoma develops in the melanocytes, the cells that give the skin its color. Usually it occurs in areas that are exposed to the sun — the arms, back, face and legs. But melanoma can also form in areas that are hidden from the sun, such as soles of the feet, between the toes, palms of the hands, and underneath finger and toe nails. It can occur in the eye, known as ocular melanoma. Melanoma can also develop inside the body, particularly in the mucus membranes that line the nose, mouth, esophagus, anus, urinary tact and vagina and are often difficult to detect.

Moles

About 30% of melanomas start in existing moles. The first step in learning about melanoma is to learn about moles, common pigmented skin lesions that can be flat or raised. There are two types of moles: normal and atypical (the medical term for atypical moles is dysplastic nevi). 10 to 15 percent of the white population have atypical moles.

Normal Mole Examples

Atypical Mole Examples

How Likely is a Mole to Develop into a Melanoma?

• The chance of melanoma developing from an ordinary mole is less than one in 3,000.
• The chance of melanoma developing from an atypical mole is about one in 100.
• Melanoma is more likely to develop from a flat or slightly raised pre-existing mole than from a fully raised mole that you have had for a long time.
• A mole with hair growing from it is no more likely to develop melanoma than a similar mole without hair.

Who is at Risk?

Ethnicity	Approx. Risk
White male	1 in 27
White female	1 in 40
Hispanic	1 in 172
Native American	1 in 200
Asian	1 in 800
Black	1 in 1,000

No one is immune to melanoma, regardless of skin color. The reggae singer Bob Marley died of melanoma in 1981 at age 36. The melanoma started under the nail of a large toe and spread to his brain. Dr. Yvedt Matory, a Boston cancer surgeon, died of melanoma in 2005 at age 48. The melanoma originated on her scalp and was hidden by her hair until it was too late.

Common locations of melanomas in the Asian, Hispanic, and African-American population are on the soles of feet, palms, between toes and fingers, and under toenails and fingernails (especially the large toenail and thumbnail).

Risk Factors

*Risk from Atypical Moles

Although visual characteristics are usually a good indicator that a mole is atypical, the only way to find out for certain is through biopsy. Some moles that look atypical may be normal upon biopsy; conversely, some moles that look normal are found to be atypical.

The risk of a single atypical mole becoming cancerous is about one in 100, compared with one in less than 3,000 for an ordinary mole. Having atypical moles removed will not entirely reduce the risk of melanoma, because people with atypical moles often develop it in clear skin rather than in moles. Think of atypical moles as “markers” that indicate a higher than average risk for melanoma even if they are all removed.

**Risk from Familial Atypical Mole Syndrome

If you have numerous large and/or irregular moles and have a parent, brother, or sister who has had melanoma, your lifetime risk of developing melanoma is 100 percent.

+Risk from Intermittent Exposure of Normally Covered Skin to Strong Sunlight

Unlike other common skin cancers, the pattern of sun exposure is important in determining melanoma risk. Intermittent exposure may be more dangerous than chronic exposure, even if the total exposure is less. Examples of intermittent exposure include:

• Summer exposure of skin covered in winter months (believed to be the reason why melanoma incidence is as high in northern states as in the most Sunbelt states, where exposure is more constant during the year).
• Taking a winter vacation in a warm, sunny climate like Florida, the Carribean, or Mexico.
• Weekend warriors who are indoors all week but outdoors on weekends.

Other Possible Risk Factors

Does Gender Matter?

Overall predicted incidence of new invasive melanoma is about 46 percent higher for males than for females, and predicted mortality is 90 percent higher for males. Incidence for white females ages 49 and younger is about 42 percent higher than for white males in the same age group. The higher incidence for younger females has been attributed to the greater use of tanning beds; the higher mortality rate for males may be due to them being less aware of their skin than females.

Is Geographic Location Important?

The risk of melanoma is similar in most US states when adjusted for age and population differences. You are as likely to develop melanoma in Massachusetts as in Florida, and almost as likely to develop it in New York as in Texas or California. Within a state, incidence tends to be higher in coastal areas and at high altitudes. Australia and New Zealand have the highest incidence of melanoma in the world, with New Zealand’s rate nearly five times the US rate. Switzerland and Norway both have higher melanoma incidence rates than the US.

Warning Signs of Melanoma

In most cases, melanoma is easy to self-detect at an early stage while it is curable by simple surgical excision. Although the visual appearance of a skin lesion (a growth or mark) is often an indication of melanoma, you cannot always rely on this alone. You should also be aware of the history of your skin lesions—any changes that occur in them, as well the onset of any new ones. The only way to develop this awareness is by regular self-examination of your skin. We recommend a complete self-skin exam once every month.

Any of these should prompt an immediate visit to a dermatologist or plastic surgeon:

• Any change in a mole, blemish, freckle, birthmark, or pigmented area
• A new mole or freckle that appears out of the blue or is growing rapidly, especially if you don’t have many moles, or the new mole or freckle looks different from those you do have
• A mole or growth that has any of the ABCD properties or all of the EFG properties shown below
• A change in surface texture or in the way a mole feels to the touch
• A new “freckle” that is dark, dry, or scaly
• A pigmented area or splotch that is new or that you don’t remember seeing before
• A new spot that is black, even if very small
• A mole or other spot that looks or behaves differently than those around it, even if it seems otherwise normal
• A mole or other spot that itches and/or bleeds
• Redness, other color, or shadow extending into the surrounding skin

There are two types of melanoma: radial and nodular. Radial melanomas are easier to self-detect because they grow in diameter near the skin surface before growing downward through the skin. Radial melanomas usually have two or more of the ABCD warning signs, as shown below.

Please note these photos show only a few of many different ways melanomas may appear; read this entire page to learn about other possible warning signs.

ABCD Properties of Radial Melanomas

Watch an Atypical Mole Change to Radical Melanoma

In the animation above, the earliest signs of an atypical mole changing into a radial melanoma are:

• increase in size
• shape becoming more irregular
• change in color

This is the time to act. As the melanoma continues to grow, its color becomes darker and less uniform, black bumps begin to appear, and in the late stages, most of the melanoma has become black and lumpy. The initial appearance of bumps often signals the last chance to act before a melanoma spreads internally.

The animation represents one of many different ways a mole can change. Usually these changes occur over a period of several weeks, or more typically, months. Although not all changes will turn out to be melanoma, don’t take any chances, and above all, don’t make the mistake of trying to be your own doctor.

The Deadly E Change

In addition to the ABCD properties, there is an E change to watch for, and if you see it you must act immediately. E equals elevation. The beginning of a bump or thickness increase in a mole, freckle, blemish, or birthmark—even if the increase is small—often signifies a melanoma that is entering a dangerous phase. Elevation changes are critical because, when the thickness of a melanoma exceeds 1 mm, the chance of internal spread increases. When the thickness reaches 3 mm, curability is only about 50 percent and quickly decreases as the thickness increases further.

The animation above shows a radial melanoma growing into the skin. Radial melanomas start in the thin outer layer of the skin (the epidermis) and at first usually undergo a surface growth phase that is noninvasive and completely curable. As the melanoma grows and reaches the middle layer of the skin (the dermis), it begins an “invasive radial” growth phase. Still, curability is about 90 percent at this point. As it penetrates further into the dermis, however, it begins an “invasive vertical” growth phase, becoming less curable as downward growth progresses into the loose connective tissue beneath the dermis (the subcutaneous layer). Malignant cells may be released into lymph and blood vessels, spreading to other parts of the body.

In short, a lump or elevation increase above the surface of the skin is a warning sign of vertical growth beneath the surface.

EFG Properties of Nodular Melanomas

About 20 percent of melanomas begin the dangerous vertical growth phase with little or no radial growth first. For these nodular melanomas the ABCD properties do not apply; instead they have all three EFG properties.

Any of the following warning signs may indicate a nodular melanoma:

• The start of a new bump in a mole, freckle, blemish, or birthmark.
• The start of a thickness increase in a previously flat or slightly raised mole.
• In otherwise clear skin, the beginning of a bump that looks like a blood blister, bubble, or pimple that continues to grow after two to three weeks, especially if you don’t ordinarily have pimples and haven’t injured yourself at the site of the blood blister.

Although a nodular melanoma can arise in a pre-existing mole, it is more common for one to develop spontaneously from normal skin, as in the four photos above. All of these were fatal. The colors of nodular melanomas are usually black, blue-black, dark brown, or brown-red. However, occasionally they are red (third photo from left), pink, grey, flesh-tone, or light to medium brown (far right photo, from the ankle of a 12-year-old boy). Nodular melanomas are typically dome-shaped and lacking ABCD properties, making visual diagnosis more difficult than for radial melanomas.

How Much Time Do You Have to Act?

• Nodular melanomas can spread internally in as little as three months.
• Most radial melanomas can spread internally within 6 to 18 months from the first noticeable change of a pre-existing mole or the appearance of a new mole.
• Radial melanomas that develop from age or liver spots (which typically occur in people 70 or older) can take as long as 10 to 15 years to begin internal spread.

The Limitations of only Visual Detection

Appearance alone is not always enough to detect early melanomas; you also need to know the history of your skin lesions, including any changes in lesions and any new lesions.

Above, the photo at left shows a mole on the toe of an adult that lacked the usual ABCD features. Ordinarily, it would not have been cause for concern, but the patient noticed it was growing larger and insisted on having it removed. It was an early melanoma. In the middle photo, the black mark under the thumbnail could easily have been attributed to an injury or a nail fungus, but the patient recalled no injury and had no history of nail fungus. It too was an early melanoma. The red lesion in the photo at right had no resemblance to a typical melanoma and might have been dismissed; however, the dermatologist recommended biopsy, which identified it as an early stage amelanotic melanoma (a melanoma lacking pigmentation).

Patient Descriptions of Melanomas in Their Own Words

No matter how many photos are included in this website, some melanomas will look different. Ginger Richardson, a melanoma survivor from Huron, Ohio, surveyed melanoma patients on the MRF Bulletin Board, asking them what their melanomas looked like when first discovered. The descriptions below portray a wide variety of appearances.

Melanomas Without Identifiable Primary Sites

About five to ten percent of melanomas are first detected in lymph nodes or internal organs without any obvious signs of primary sites on the skin. Most dermatologists believe these originate from 1) moles or misdiagnosed melanomas that were incompletely removed, or 2) “regressed” melanomas in which the immune system eradicated cancerous cells on the skin, but not before some cells were released into lymph or blood vessels.

Any mole that is changing should be examined by a dermatologist or plastic surgeon immediately. Although most malignant changes involve increasing size and darkening color, some cancerous moles can actually decrease in size, become lighter, and even disappear. The rate of decreasing size and fading color is important; a very gradual change over a period of years is often benign, while a rapid change over a period of weeks or months is often malignant. Even though a cancerous mole can fade from the skin’s surface, it can still grow deep enough below the surface to release melanoma cells into the lymph fluid or bloodstream.

Many skin growths that look ominous may be harmless. The six skin lesions in the photos above may look like melanomas to viewers untrained in dermatology. However, all were benign.