Most melanomas announce themselves visually before they become dangerous, and learning what to look for gives you a real advantage. When caught at an early, localized stage, melanoma has a 97.6% five-year survival rate. That number drops sharply once it spreads to lymph nodes (60.3%) or distant organs (16.2%). The difference between those outcomes often comes down to how quickly someone noticed something off about a spot on their skin.
The ABCDE Rule
Dermatologists use a five-feature checklist to evaluate suspicious moles. Each letter stands for a visual characteristic that distinguishes melanoma from ordinary spots:
- Asymmetry: One half of the mole doesn’t match the other. Normal moles tend to be roughly symmetrical.
- Border: The edges are ragged, notched, or blurred rather than smooth and well-defined. Pigment may bleed outward into surrounding skin.
- Color: Multiple shades appear within the same spot. You might see a mix of brown, tan, and black, or patches of white, gray, red, pink, or blue.
- Diameter: Most melanomas are larger than 6 millimeters, roughly the size of a pencil eraser. But melanomas can also be smaller than this, so size alone isn’t reassuring.
- Evolving: The mole has changed in size, shape, or color over the past weeks or months. Any noticeable change in an existing mole deserves attention.
You don’t need all five features to be concerned. A single one, especially the “E” for evolving, is enough reason to get a professional evaluation. The ABCDE system works well for the most common type of melanoma, which grows outward across the skin’s surface before invading deeper. It’s less reliable for certain subtypes, including nodular melanoma (which grows downward quickly) and melanomas that lack pigment entirely.
The Ugly Duckling Sign
Your moles generally share a family resemblance. They tend to look similar to one another in color, size, and shape. The “ugly duckling” approach takes advantage of that pattern: instead of analyzing each mole in isolation, you scan for the one that looks nothing like the rest.
This method catches melanomas that might technically pass individual ABCDE criteria but still stand out as different from your personal baseline. A dark, irregular mole on someone whose other moles are small and uniform is suspicious for that reason alone. French researchers tested this approach and found it roughly as effective as applying formal diagnostic criteria to each mole individually. In practice, the two methods work best together: scan your body for outliers, then examine any outlier against the ABCDE checklist.
Melanomas That Don’t Look Like Melanomas
Not all melanomas are dark brown or black. Amelanotic melanomas lack significant pigment and can appear pink, red, or even skin-colored. Early lesions often look like a flat, asymmetrical patch that’s uniformly pink or red, sometimes with faint tan or gray coloring at the edges. More advanced nodular forms can resemble an ordinary skin-colored bump. These melanomas are easier to miss precisely because they don’t trigger the “dark, irregular mole” alarm most people rely on. A new pink or red spot that persists, grows, or doesn’t heal warrants the same scrutiny as a dark mole.
Melanoma on Palms, Soles, and Nails
Acral lentiginous melanoma develops exclusively on the palms, soles, and under the nails. It’s the most common type of melanoma in people with darker skin tones, and it occurs in areas that get little to no sun exposure, which means standard sun-damage awareness campaigns often miss it entirely.
On the palms or soles, it typically appears as an unevenly pigmented black or brown spot that looks different from the surrounding skin and grows over time. Under a nail, it shows up as a pigmented streak or band of color running from the cuticle to the tip of the nail. A helpful screening tool for these locations uses the acronym CUBED: Color that’s unusual, Uncertain diagnosis, Bleeding, Enlargement, and Delay in healing. If a spot on your hands or feet matches two or more of those features, it’s worth having examined.
How to Do a Thorough Self-Exam
A full skin check takes about 10 minutes and should cover every surface, including areas you wouldn’t think to look. You’ll need a full-length mirror, a handheld mirror, and good lighting. The Skin Cancer Foundation recommends doing this monthly.
Start with your scalp. Use a blow dryer to part your hair in sections and expose the skin underneath. Check your face, ears (including behind them), and neck. Move to your hands: examine the palms, the backs, between each finger, and under every fingernail. Work up your forearms and scan all sides of your upper arms.
Use the full-length mirror for your chest, torso, and sides. With the handheld mirror, check your upper and lower back, the backs of your neck and ears, and your buttocks. Then sit down and prop each leg up to inspect the fronts, sides, and backs of your thighs and shins. Finish with your ankles, the tops and soles of your feet, between your toes, and your toenails. If you wear nail polish on your toes, remove it periodically so you can see the nail bed.
The most commonly missed areas are the scalp, the soles of the feet, behind the ears, and between the toes. These are also the spots where melanoma can grow unnoticed for the longest time.
What Happens if a Spot Looks Suspicious
No visual assessment, whether by you or even a dermatologist, can definitively diagnose melanoma. Diagnosis requires a biopsy, where tissue is removed and examined under a microscope. Your dermatologist will likely use a dermatoscope first, a handheld magnifying device with polarized light that reveals structures invisible to the naked eye. Features like irregular pigment networks, blue-white veils, and unusual blood vessel patterns help distinguish melanoma from benign moles.
If a biopsy is needed, the preference is to remove the entire suspicious spot rather than sampling just a piece of it. Two common approaches are a punch biopsy, where a small circular blade cores out the lesion and surrounding tissue, and an excisional biopsy, where a scalpel removes the entire mole plus a margin of healthy skin. Both are done under local anesthesia in the office. Results typically come back within one to two weeks.
Getting a biopsy doesn’t mean you have cancer. The majority of biopsied moles turn out to be benign. But the only way to rule melanoma out with certainty is to look at the cells under a microscope, so avoiding the biopsy isn’t a safer bet than getting one.
Who Needs to Be Extra Vigilant
Certain factors raise your risk enough to justify more frequent self-exams and professional skin checks. Having more than 50 ordinary moles, or any number of atypical moles (moles that are large, irregularly shaped, or multicolored), puts you in a higher-risk category. A personal or family history of melanoma significantly increases your odds. Fair skin, a history of blistering sunburns, and extensive UV exposure from sun or tanning beds all contribute. If you’re immunosuppressed for any reason, your skin cancer surveillance should be more aggressive.
People with darker skin tones have lower overall melanoma rates, but their melanomas are more likely to be diagnosed at a later stage, partly because of lower awareness and partly because acral lentiginous melanoma on palms, soles, and nails doesn’t fit the typical picture most people are taught to watch for. Regardless of skin tone, any new or changing spot that persists beyond a few weeks deserves a closer look.