Early skin cancer usually shows up as a small change on your skin that doesn’t go away: a shiny bump, a scaly patch, a sore that won’t heal, or a mole that starts looking different from the others. The specific appearance depends on which type of skin cancer is developing, and the three main types each have distinct early warning signs. When caught at the localized stage, melanoma has a 97.6% five-year survival rate, so recognizing these changes early matters enormously.
Basal Cell Carcinoma: The Most Common Type
Basal cell carcinoma accounts for the majority of skin cancers and tends to grow slowly. In its earliest stage, it typically appears as a small, shiny bump that looks slightly translucent, almost like you can see a bit through its surface. On lighter skin, this bump looks pearly white or pink. On brown and Black skin, it often appears brown or glossy black. You may notice tiny blood vessels running across the surface, though these can be harder to spot on darker skin tones.
Not all basal cell carcinomas start as bumps, though. Some begin as flat, scaly patches with or without a raised edge that grow larger over time. Others look like a white, waxy, scar-like area without a clearly defined border. One of the most telling signs is a sore that bleeds, scabs over, and then reopens. If you have a spot that keeps cycling through healing and re-opening over several weeks, that pattern alone is worth getting checked.
Squamous Cell Carcinoma: Rough and Scaly
Squamous cell carcinoma often feels rough before it looks alarming. The earliest sign is frequently a firm bump or a flat sore with a scaly, crusty surface. The bump can be the same color as your surrounding skin, or it may appear pink, red, brown, or black depending on your skin tone. It sometimes resembles a wart.
Pay attention to your lips, too. A rough, scaly patch on the lip that eventually becomes an open sore can signal squamous cell carcinoma, as can sores or rough patches inside the mouth. This type also has a habit of developing on top of old scars or long-standing sores, appearing as a new raised area in damaged skin you thought was stable.
Melanoma: The ABCDE Rule
Melanoma is less common than basal or squamous cell carcinoma but far more dangerous if it spreads. It typically starts in or near an existing mole, though it can also appear as an entirely new spot. The National Cancer Institute uses five features, known as the ABCDE rule, to describe what early melanoma looks like:
- Asymmetry: One half of the mole doesn’t match the other. Normal moles are generally symmetrical.
- Border irregularity: The edges are ragged, notched, or blurred rather than smooth. The pigment may look like it’s spreading into the surrounding skin.
- Color variation: Instead of one uniform shade, you see a mix of brown, tan, and black, sometimes with patches of white, gray, red, pink, or blue.
- Diameter: Most melanomas are larger than 6 millimeters (about the size of a pencil eraser) when diagnosed, though they can be smaller.
- Evolving: The mole has changed in size, shape, or color over the past few weeks or months. Any mole that is actively changing deserves attention.
Of these five, “evolving” is arguably the most useful for everyday self-checks. A mole that looked fine six months ago but now looks different, itches, bleeds, or has grown is the kind of change that should prompt a visit to a dermatologist, even if it doesn’t check every other box on the list.
The Ugly Duckling Sign
Beyond the ABCDE rule, there’s a simpler method that works well during a self-exam. It’s called the “ugly duckling” sign: look for the one mole that doesn’t match the rest. Most people’s moles share a general family resemblance in color, size, and shape. If one mole stands out as clearly different from all your others, that outlier deserves closer scrutiny, even if it doesn’t obviously fit the ABCDE criteria.
What Early Skin Cancer Looks Like on Darker Skin
Skin cancer presentations can look different on brown and Black skin, and these differences contribute to later-stage diagnoses in people of color. The most common form of melanoma in people with dark skin is acral lentiginous melanoma, which doesn’t appear in the sun-exposed areas most people think to check. Instead, it shows up on the palms of the hands, the soles of the feet, and on fingers, toes, and nail beds.
Under a fingernail or toenail, this type of melanoma looks like a dark band or streak running lengthwise. If a dark band under your nail begins to widen or spread, that’s a significant warning sign. On the palms or soles, it can appear as a dark, irregularly shaped patch that may be mistaken for a bruise or stain. Because these locations aren’t typically associated with skin cancer, they’re easy to overlook during routine checks.
Basal cell carcinoma also looks different on darker skin. Rather than the pearly pink bump seen on lighter skin, it often appears brown or glossy black, which can be confused with a normal mole. Tiny blood vessels on the surface, a hallmark clue, are harder to see against darker skin.
Precancerous Spots to Watch
Not every concerning spot is cancer yet. Actinic keratoses are rough, dry, scaly patches that develop on sun-exposed skin and can eventually progress to squamous cell carcinoma if left untreated. They’re usually less than an inch across and show up on the head, neck, hands, and forearms. They can be pink, red, or brown, and they often feel like sandpaper before they’re clearly visible. Some itch, burn, or occasionally bleed.
These patches are worth treating precisely because they sit on the boundary between harmless and harmful. A dermatologist can remove them with straightforward in-office treatments, effectively stopping the progression before it becomes cancer.
Rare Types Worth Knowing
Merkel cell carcinoma is uncommon but aggressive. It appears as a painless bump on the skin that grows quickly, often over just a few weeks. The bump may look pink, purple, red-brown, or skin-colored. Speed of growth is the distinguishing feature here. Most benign bumps and even most common skin cancers grow slowly. A new, firm bump that seems visibly larger week to week is unusual and worth urgent evaluation.
How to Do a Self-Check
The key to catching skin cancer early is knowing what your skin normally looks like so you can spot when something changes. A thorough self-exam once a month covers your entire body, including areas that don’t get sun exposure. Use a full-length mirror and a hand mirror together to check your back, the backs of your legs, and your scalp. Check between your toes, the soles of your feet, your palms, and under every fingernail and toenail.
You’re looking for anything new, anything that has changed, and anything that doesn’t heal. A pimple resolves in a week or two. A skin cancer doesn’t. A mole that has looked the same for years is generally not a concern. A mole that is darker this month than last month is. That pattern of persistence and change is the thread that connects every type of skin cancer at its earliest, most treatable stage.