A cancerous mole typically looks uneven, multicolored, and different from the other spots on your skin. It may have jagged borders, mix several shades of brown or black, and measure larger than 6 millimeters across (roughly the size of a pencil eraser). But not all skin cancers follow that pattern, and some look nothing like a dark mole at all.
The ABCDE Signs of Melanoma
Dermatologists use a five-letter checklist to flag suspicious moles. You don’t need all five features for a mole to be dangerous, but each one raises the level of concern.
- Asymmetry. One half of the mole doesn’t mirror the other. Normal moles tend to be roughly round or oval and symmetrical.
- Border. The edges look ragged, notched, or blurred rather than smooth. The pigment may bleed outward into the surrounding skin.
- Color. Instead of a single uniform shade, the mole contains a mix of brown, tan, and black. You might also see patches of white, gray, red, pink, or blue within the same spot.
- Diameter. Most melanomas are larger than 6 millimeters wide when diagnosed, though they can start smaller. Any mole that’s growing deserves attention regardless of its current size.
- Evolving. The mole has changed in size, shape, color, or height over recent weeks or months. New symptoms like itching, crusting, or bleeding also count as evolution.
Surface Changes That Signal Trouble
Beyond shape and color, pay attention to how a mole feels and behaves on the surface. A mole that bleeds without being scratched or injured is a possible sign of melanoma. Crusting, oozing, or scabbing that doesn’t heal within a couple of weeks is another red flag. Some cancerous moles develop a raised, lumpy texture in an area that was previously flat. These surface changes often prompt people to finally get a spot checked, and they’re worth taking seriously even if the mole otherwise looks unremarkable.
The “Ugly Duckling” Approach
Most of your moles probably share a family resemblance. They’re similar in size, color, and shape. The ugly duckling sign refers to the one spot that breaks the pattern. Maybe it’s darker than the rest, more raised, scabbed over, or just looks “off” compared to its neighbors. This method is especially useful if you have a lot of moles and find the ABCDE criteria hard to apply to each one individually. Instead of analyzing every spot, you’re scanning for the outlier.
Melanoma That Doesn’t Look Like a Dark Mole
About 5 percent of melanomas are amelanotic, meaning they lack the dark pigment most people associate with skin cancer. These show up as pink, red, or flesh-colored spots on the skin. Because they don’t match the classic image of a dark, irregular mole, they’re often mistaken for a pimple, bug bite, or scar. That confusion leads to later diagnoses on average compared with brown or black melanomas. If you have a pink or reddish spot that persists for weeks and doesn’t respond to typical wound healing, it’s worth having examined.
What It Looks Like on Darker Skin
On brown and Black skin, melanoma most commonly appears in places that get little sun exposure: the palms of the hands, the soles of the feet, and under the nails. This type, called acral lentiginous melanoma, often looks like an unevenly pigmented brown or black spot on the palm or sole that grows over time. Under a fingernail or toenail, it can appear as a dark streak running from the cuticle to the tip of the nail.
People frequently mistake these spots for bruises, blood blisters, or warts. Because skin cancer is less common in people with darker skin, many don’t think to check these areas or realize what they’re seeing. A helpful screening tool for spots on the hands, feet, and nails uses the acronym CUBED: Color that’s unusual for you, Uncertain diagnosis, Bleeding, Enlargement, and Delay in healing.
Non-Melanoma Skin Cancers Look Different
Not all skin cancer starts in a mole. Basal cell carcinoma, the most common type, often appears as a shiny, slightly translucent bump with a pearly or waxy surface. On lighter skin it looks pink or white. On darker skin it can appear brown or glossy black. Tiny blood vessels sometimes show through the surface, and the bump may bleed and scab over repeatedly. Some basal cell carcinomas look like flat, scaly patches or pale, scar-like areas with no clear border.
Squamous cell carcinoma tends to show up as a firm nodule or a flat sore with a scaly crust. The color varies with skin tone, ranging from pink and red to brown or black. It can also appear as a rough, scaly patch on the lip, a sore inside the mouth, or a wart-like growth. A key feature of both types: they’re persistent. Unlike a cut or rash, they don’t heal on their own and tend to slowly grow over weeks to months.
How Quickly a Cancerous Mole Changes
There’s no single growth rate for skin cancer. Some melanomas can spread within a few months, while others develop so gradually that changes are nearly invisible from week to week. One slow-growing form can evolve over decades as a faint, flat patch before becoming invasive. Fast-growing types can go from a small spot to a thickened, raised lesion in a matter of months. This unpredictability is exactly why tracking changes matters. If you photograph your moles every few months, you create a baseline that makes even subtle shifts easier to spot. Changes in size, shape, color, or texture over any timeframe are the core warning sign.