Melanoma caught early, before it spreads beyond the skin, has a 97.6% five-year survival rate. Once it reaches distant organs, that number drops to 16.2%. The difference between those two outcomes often comes down to spotting a suspicious mole weeks or months sooner. Here’s how to give yourself the best chance.
The ABCDE Rule for Suspicious Moles
The most widely used framework for evaluating moles is the ABCDE checklist, developed by the National Cancer Institute. Each letter flags a feature that distinguishes melanoma from a normal mole:
- Asymmetry: One half of the mole doesn’t match the other in shape.
- Border: The edges are ragged, notched, or blurred rather than smooth. Pigment may bleed into the surrounding skin.
- Color: Instead of a single uniform shade, the mole contains mixed shades of brown, tan, and black, sometimes with patches of white, gray, red, pink, or blue.
- Diameter: Most melanomas are larger than 6 millimeters, roughly the size of a pencil eraser, though they can be smaller.
- Evolving: The mole has changed in size, shape, or color over recent weeks or months.
A mole doesn’t need to hit all five criteria to be suspicious. Any single feature, especially “evolving,” warrants a closer look. Change over time is the most reliable warning sign because even benign-looking moles can become dangerous if they’re actively shifting.
The Ugly Duckling Sign
Your moles tend to look like each other. They share a similar color, size, and pattern. A melanoma often breaks that pattern, standing out as the “ugly duckling” among its neighbors. This concept is surprisingly effective: in clinical testing, it correctly identified melanoma about 86% of the time, and non-clinicians performed nearly as well as dermatologists when using it. If one mole on your body looks noticeably different from all the rest, that’s the one to get checked.
Nodular Melanoma Doesn’t Follow the Rules
Not every melanoma looks like a dark, irregular flat spot. Nodular melanoma, one of the more aggressive types, often appears as a raised, dome-shaped bump that can be skin-colored, pink, red, or dark. It grows fast and doesn’t always trigger the classic ABCDE warning signs. For these lesions, a separate set of criteria applies: EFG.
- Elevated: The lesion is raised above the skin surface.
- Firm: It feels solid to the touch, not soft or squishy.
- Growing: It has noticeably changed over days to weeks, not the slow evolution typical of benign spots.
Rapid growth is the key differentiator here. Benign skin lesions tend to remain stable or change gradually over years. A firm, raised bump that appears and grows within a few weeks should be evaluated promptly.
Where Melanoma Hides
Melanoma doesn’t only develop on sun-exposed skin. It can appear in places most people never think to check. The palms, soles of the feet, and skin between the toes are common sites for acral lentiginous melanoma, a subtype that disproportionately affects people with darker skin tones.
Under the fingernails and toenails, melanoma shows up as a dark streak running lengthwise through the nail. When the pigmentation extends from the nail onto the surrounding skin fold, it’s called Hutchinson’s sign, and it’s a red flag for melanoma. A new dark line under a single nail that wasn’t caused by injury deserves attention.
The scalp, behind the ears, and between the buttocks are other frequently missed locations. These areas are difficult to see on your own, which is exactly why a systematic self-exam matters.
How to Do a Full-Body Skin Check
You need a full-length mirror, a hand mirror, and good lighting. The American Academy of Dermatology recommends the following routine:
- Front and back: Stand before the full-length mirror. Look at your entire body from the front, then turn and examine the back. Raise both arms and check each side.
- Arms and hands: Bend your elbows and carefully inspect your forearms, upper arms, underarms, fingernails, and palms.
- Legs and feet: Examine the backs of your legs, the tops and soles of your feet, the spaces between each toe, and your toenails.
- Scalp and neck: Use the hand mirror to check the back of your neck. Part your hair in sections to look at your scalp, or ask someone to help.
- Back and buttocks: Use the hand mirror (or a partner) to examine your lower back and buttocks.
The goal is to learn the map of your own skin so that changes stand out. Taking photos of moles with your phone creates a visual record you can compare month to month. This is especially useful for moles on your back or other hard-to-see areas where subtle changes are easy to miss.
How Often You Need Professional Screening
The U.S. Preventive Services Task Force currently says there isn’t enough evidence to recommend routine skin cancer screening for all adults who have no symptoms or risk factors. But that guidance explicitly doesn’t apply to people with a personal or family history of skin cancer, or anyone who has noticed changes in their moles. If you fall into those categories, regular dermatology visits are appropriate.
Your individual risk profile shapes how often you should be seen. People with a higher total mole count carry incrementally more risk: research from the University of Queensland found that each additional mole on the body increases melanoma risk by about 2%. A person with 50 more moles than average has meaningfully higher cumulative risk. Fair skin, a history of blistering sunburns, and a first-degree relative with melanoma all shift the equation further.
What Happens at a Dermatologist’s Visit
A dermatologist uses a tool called a dermatoscope, essentially a magnifying lens with polarized light, to examine suspicious moles at a level of detail impossible with the naked eye. This technique improves diagnostic accuracy for melanoma by about 49% compared to looking at the skin without magnification. The catch is that dermatoscopy only outperforms a visual exam in the hands of experienced clinicians. The tool itself isn’t magic; the training behind it is what matters.
If a mole looks suspicious under dermatoscopy, the next step is a biopsy, where a small sample of the lesion is removed and examined under a microscope. This is the only way to confirm whether a mole is melanoma. The procedure is quick, done under local anesthesia, and typically leaves a small scar.
AI Skin Apps and Their Limits
Smartphone apps that use artificial intelligence to analyze photos of moles are becoming more common, and the FDA has cleared at least one AI-powered tool for clinical use. But that tool is designed for physicians, not consumers, and it evaluates lesions that a doctor has already identified as suspicious. It’s a second-opinion tool, not a primary screening device.
Consumer mole-tracking apps can be useful for documenting changes over time, giving you side-by-side photos to share with your dermatologist. They are not reliable replacements for a trained eye, and a reassuring result from an app should never override your own concern about a changing mole. If something on your skin looks wrong to you, that instinct is worth acting on regardless of what any app says.
Why Timing Matters So Much
About 83% of melanomas are diagnosed while still localized to the skin, which is part of why the overall five-year survival rate sits above 90%. The biology is straightforward: melanoma that stays in the top layers of the skin can be removed surgically with excellent outcomes. Once it penetrates deeper and reaches lymph nodes, survival drops to around 60%. At stage IV, when it has spread to distant organs, only about 1 in 6 patients survives five years.
Every week a melanoma goes unnoticed, it grows thicker. Thickness at the time of diagnosis, measured in millimeters, is the single strongest predictor of outcome. A monthly self-exam takes about 10 minutes. Given what’s at stake, it’s one of the highest-return habits you can build.