Saving lives through education


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.

Origin of MelanomaApprox. %
     Clear skin
     Includes under toenails and fingernails
     Pre-existing moles30%
     Age spots (liver spots)
     Usually occurs in people in their 70s or older
Mucus membranes2%
Remote internal site0.2%


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
example of a flat ordinary mole
A flat ordinary mole
(Arthur C. Huntley, MD)
example of a raised ordinary mole
A raised ordinary mole
(National Cancer Institute)
Atypical Mole Examples
example of a flat atypical mole
A flat atypical mole
(National Cancer Institute)
example of a raised atypical mole
A raised atypical mole
(National Cancer Institute)
Normal Moles
have ALL these features
Atypical Moles
have one or more of these features
Round or oval shapeIrregular shape
Sharp, even borders with skinUneven and/or fuzzy borders with skin
Uniform color (usually brown)Two or more shades of brown or pink
Less than 1/4 inch wide1/4 inch wide or more
Cauliflower or smooth surfaceCauliflower or smooth surface
Even dome shape if mole is raisedFlat edges with “fried egg” center if mole is raised

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?

EthnicityApprox. Risk
White male1 in 27
White female1 in 40
Hispanic1 in 172
Native American1 in 200
Asian1 in 800
Black1 in 1,000
melanoma toenail
A melanoma under a toenail, easily mistaken for a nail fungus. (Dr. J. Ashworth)
Bob Marley (left) and Dr. Yvedt Matory (right)

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

Uncontrollable Risk FactorRisk Multiplier
(or Risk %)
50 or more normal moles2–4x
One atypical mole*2x
Red or blond hair, blue or green eyes, and/or a light complexion2–3x
Heavily freckled with no atypical moles3x
Personal history of non-melanoma skin cancer3–5x
Undergoing immunosuppresant treatment or medication4–8x
10 or more atypical moles*12–14x
Heavily freckled with many atypical moles but no family history of melanoma*20x
Personal history of melanoma9–28x
Two immediate family members (parent, child, sibling) have had melanoma100%
Many atypical moles and one immediate family member has had melanoma**100%
Having certain skin diseases such as lupus or xeroderma pigmentosumVery High
Taking a photosensitizing medication or treatmentUnknown
Controllable Risk FactorsRisk Multiplier
(or Risk %)
Intermittent exposure of normally covered skin to strong sunlight+High
One blistering sunburn under age 202x
Three or more blistering sunburns under age 205x
One tanning bed session under age 351.22x
10 or more tanning bed sessions in a year under age 307.7x

*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.

showing atypical moles on a man’s back
Atypical mole syndrome on man’s back

**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

example of an asymmetrical melanoma
Radial melanomas are often unsymmetrical; an imaginary line through the middle does not produce matching halves. (
example of uneven borders in a melanoma mole

The borders of radial melanomas may be uneven, fuzzy, or have notched or scalloped edges. (
example of melanoma mole that begins to displays different colors
Radial melanomas often begin to show color changes in areas, with shades of black, brown, tan, and sometimes other colors. (
example of a mole growing larger than the width of a pencil eraser
Unlike normal or atypical moles, radial melanomas often grow larger than the width of a pencil eraser. (

Watch an Atypical Mole Change to Radical Melanoma

animation showing atypical mole changing 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

An animation showing melanoma growing through skin layers

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.

example of an elevated melanoma
This elevated melanoma started in a mole that grew darker and larger, then developed a bump on the left side. At this stage, it was destined to be fatal. If it had been removed while it was flat, or even when the bump first started developing, it likely would have been curable. (National Cancer Institute)

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.

E = ELEVATEDEarly elevation above the skin surface
F = FIRMFirm to the touch, not flabby
G = GROWINGContinues growing more than two to three weeks

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.
examples of nodular melanoma
(From left: Rebecca C. Tung, MD/Cleveland Clinic;; Jeffrey L. Melton, MD/ Loyola University; University of Michigan Comprehensive Cancer Center)

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.

animation of nodular melanoma developing on clear skin
Watch the simulation of nodular melanoma developing in clear skin.

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.

(Arthur C. Huntley, MD; SKINmed)

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.

“Dusty gray blotch.”

“Pale flat spot that sometimes itched and would flake off when scratched.”

“Flesh-colored on the crown of head, started by looking like tip of an eraser then got itchy, tingled, and became more irregular.”

“Pale, flat spot… had since a child, irregular borders, lighter than other freckles.”

“Perfectly round, flat, and evenly-colored brown. No itching, bleeding, or scab.”

“Dry patch of skin that was quite itchy.”

“Flat light brown freckles… started to merge.”

“Mole got larger and lighter in color. Sort of greyish. Looked like a snake about to molt.”

“Little round black spot… under direct sunlight one could see various colors.”

“Mole that was colorless; same as color of skin. Developed a red circle around it. Over a couple of years the scar seemed to spread out into a circle. Began to itch.”

“Small, even-colored brown mole… appeared quickly and grew quickly… started itching… skin around it was red… started oozing and [became] crusty and black [in areas]… started bleeding.”

“Freckle that grew and looked like clover with hole in middle.”

“Looked exactly like a wart—so much that not much attention was paid to it until it started bleeding.”

“Smallish pink circle, flat, looked like a burn mark. No bigger than 5 mm diameter. Grew off an old, very small mole that was also pink.”

“Reddish-brown, on nose, seemed like a pimple, never completely healed… not concerned until it bled.”

“A pimple… had it as a child.”

“Small, perfectly round red bump [that] looked like a pimple.”

“Size/shape/texture of a large mosquito bite but was dark brown [and] did not itch like a bug bite.”

“Flesh-colored and regular in shape… looked like a pencil eraser… raised.”

“Like a scab, irregular borders and itchy, on the exact site of a [longtime] double-sized freckle.”

Melanomas Without Identifiable Primary Sites

A melanoma with partial regression. The light pink areas of scar tissue indicate where the immune system has eradicated some of the cancerous cells. (Arthur C. Huntley, MD)

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.

(All photos:

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.

The Melanoma Education Foundation is devoted to educational purposes only and is not engaged in rendering medical advice or professional services. Information provided by the Foundation should not be used for diagnosing or treating a skin problem or disease. It is not a substitute for professional care. If you have or suspect you have a skin problem you should consult a dermatologist, plastic surgeon, or other professional healthcare provider.