Skin cancer usually starts as a small, unremarkable spot that’s easy to dismiss: a shiny bump, a scaly patch that won’t go away, or a mole that looks slightly different from the others. What it looks like depends on the type of skin cancer, your skin tone, and where it appears on your body. Knowing the specific visual clues for each type gives you the best chance of catching it early, when treatment is simplest.
Basal Cell Carcinoma: The Most Common Type
Basal cell carcinoma accounts for the majority of skin cancers, and its earliest forms can look surprisingly harmless. On lighter skin, it often appears as a firm, raised, round growth that’s shiny and pink or red. On darker skin tones, that same bump tends to be brown, black, or blue. Sometimes the growth is the exact same color as your skin, making it easy to overlook entirely.
There are a few other patterns to watch for. Some basal cell carcinomas develop a small dip or depression in the center, which may scab over and bleed. Others look like a rough, scaly patch, and some people develop several of these patches at once. One particularly tricky presentation resembles a freckle or age spot, but feels scaly or rough when you run your finger over it. A sore that heals, comes back, and then heals again (or never fully heals) is another classic early sign.
Squamous Cell Carcinoma: Scaly Spots That Persist
Squamous cell carcinoma typically starts as a flat sore with a crusty, scaly surface, or as a firm bump (called a nodule) that can be pink, red, brown, or black depending on your skin color. It tends to show up on sun-exposed areas like the face, ears, hands, and forearms, but it can also appear on the lips, inside the mouth, or on the genitals.
The key warning sign is persistence. A sore or scab that hasn’t healed in about two months, or a flat scaly patch that simply won’t resolve, deserves a closer look. A new raised area developing on an old scar is another red flag. On the lips, it may start as a rough, scaly patch that eventually breaks open into an ulcer.
Precancerous Patches That Can Progress
Before squamous cell carcinoma develops, many people first get precancerous spots called actinic keratoses. These are rough, dry, scaly patches usually less than an inch across, caused by years of cumulative sun exposure. They feel like sandpaper when you touch them. Colors range from pink to red to brown, and over time some develop a hard, wartlike surface. About 5% to 10% of untreated actinic keratoses eventually progress to squamous cell carcinoma, so treating them early removes the risk.
Melanoma: The ABCDE Checklist
Melanoma is less common than basal or squamous cell carcinoma but far more dangerous. It often starts in or near an existing mole, though it can also appear on previously clear skin. The National Cancer Institute’s ABCDE rule captures what early melanoma typically looks like:
- Asymmetry: One half of the spot doesn’t match the other.
- Border irregularity: The edges are ragged, notched, or blurred rather than smooth and round. Pigment may spread into the surrounding skin.
- Color that is uneven: Instead of a single 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), though they can be smaller.
- Evolving: The spot has changed in size, shape, or color over the past few weeks or months.
Of all five features, “evolving” is arguably the most important. Any mole that is visibly changing deserves attention, even if it doesn’t check every other box.
Melanomas That Don’t Follow the Rules
Not every melanoma looks like a dark, irregular mole. About 5% of melanomas are amelanotic, meaning they have little or no pigment. These show up as pink or red spots on the skin rather than brown or black ones. Because they look so much like harmless irritation or a pimple, amelanotic melanomas are often diagnosed later than pigmented ones.
Nodular melanoma is another exception. Instead of spreading outward across the skin first, it grows downward quickly, appearing as a raised, firm bump that gets bigger over weeks. It may be black, blue, red, or even skin-colored. Because it’s often round and uniform, it can slip past the ABCDE criteria. A more useful check for this type is the EFG rule: elevated above the skin surface, firm to the touch, and growing noticeably.
What Skin Cancer Looks Like on Darker Skin
Skin cancer is less common in people with darker skin, but it’s often diagnosed at a later, more advanced stage because both patients and doctors may not expect it. The most common form of melanoma in people with dark skin is acral lentiginous melanoma, which appears in places that don’t get much sun: the palms of the hands, the soles of the feet, and under the fingernails or toenails.
On a palm or sole, it looks like a dark, irregularly shaped patch. Under a nail, it appears as a dark vertical band running from the base of the nail to the tip. If that dark band starts widening, or if the skin around the nail begins to darken (a finding called Hutchinson’s sign), those are strong warning signs. Checking your nails, palms, and soles during self-exams is especially important if you have dark skin, since these are the highest-risk locations.
The Ugly Duckling Method
Beyond memorizing specific criteria, one of the most practical ways to spot a suspicious spot is the “ugly duckling” approach. Most of your moles share a general family resemblance: similar size, color, and shape. A melanoma often stands out as the one that doesn’t match. It might be noticeably darker, lighter, larger, or smaller than its neighbors. An isolated mole sitting alone in an area without other moles for comparison also counts as an ugly duckling worth watching.
This method works well because it uses your own body as the baseline. You don’t need to memorize clinical terms. You just need to notice which spot doesn’t look like the rest.
How to Check Your Own Skin
There are currently no formal U.S. guidelines recommending routine skin cancer screening for people without symptoms or risk factors. That makes self-awareness your first line of defense. A monthly self-check, done in good lighting with a full-length mirror and a hand mirror for hard-to-see areas, is a simple habit that helps you notice changes early.
Pay attention to your full body, not just sun-exposed areas. Check between your toes, the soles of your feet, your scalp (use a blow dryer to part your hair in sections), behind your ears, and under your nails. What you’re looking for isn’t perfection in identifying a specific cancer type. You’re looking for anything new, anything changing, and anything that looks different from the spots around it. If a spot is growing, bleeding, crusting, or refusing to heal over a couple of months, that’s your signal to get it evaluated.