Early skin cancer usually appears as a small spot that looks slightly “off” compared to the skin around it. It might be a shiny bump, a scaly patch that won’t heal, or a mole that has started changing shape or color. The specific appearance depends on the type of skin cancer, and the three most common types each look quite different from one another.
Basal Cell Carcinoma: The Most Common Type
Basal cell carcinoma accounts for the majority of skin cancer cases, and it often looks deceptively minor. On lighter skin, it typically appears as a small, slightly transparent or pearly bump that’s skin-colored or pink. On darker skin tones, it often shows up as a brown or glossy black bump with a rolled border. You might notice tiny blood vessels running across the surface, though these can be harder to spot on darker skin.
Not all basal cell carcinomas look like bumps. Some present as a flat, scaly patch with or without a raised edge. Others resemble a white, waxy, scar-like area without a clearly defined border. One hallmark of early basal cell carcinoma is a spot that bleeds, scabs over, heals partially, then bleeds again. This cycle of bleeding and crusting in the same spot is a strong signal that something beyond normal skin irritation is going on.
Squamous Cell Carcinoma: Rough, Scaly Patches
Squamous cell carcinoma tends to look rougher and more textured than basal cell. Early signs include a firm bump (nodule) on the skin that can be pink, red, brown, or black depending on skin tone. It can also appear as a flat sore topped with a scaly crust, or a new raised area developing on an old scar or wound.
The lips are a common location. A rough, scaly patch on the lip that eventually becomes an open sore is a classic early presentation. Squamous cell carcinoma can also develop inside the mouth as a sore or rough patch. Lesions that are larger than 1 centimeter, bleeding, hardening, or growing rapidly warrant closer evaluation.
Melanoma: The ABCDE Checklist
Melanoma is less common than basal or squamous cell carcinoma but far more dangerous when caught late. Dermatologists use a five-letter checklist to help identify it early:
- Asymmetry: One half of the mole doesn’t match the other half. A normal mole is roughly round or oval and looks the same on both sides.
- Border: The edges are ragged, notched, or blurred rather than smooth and distinct. Pigment may appear to spread into the surrounding skin.
- Color: The color is uneven. You might see shades of brown, tan, and black within the same spot, or even areas of white, gray, red, pink, or blue.
- Diameter: The spot is larger than about 6 millimeters, roughly the size of a pencil eraser. Melanomas can be smaller than this, but growth beyond that threshold is a warning sign.
- Evolving: The mole has changed in size, shape, or color over the past few weeks or months.
For comparison, a normal mole is typically round or oval with a smooth, distinct edge and an even color of pink, tan, or brown. It stays stable over time. The key difference with melanoma is change and irregularity.
The “Ugly Duckling” Approach
Beyond the ABCDE checklist, there’s a simpler concept that catches melanomas the checklist sometimes misses. Most of your moles tend to look similar to each other. The “ugly duckling” sign means spotting the one mole that looks noticeably different from all the others on your body. It might be darker, larger, or just a different shape. If one mole stands out as the odd one in the group, that’s the one worth having examined.
Melanoma That Doesn’t Look Like Melanoma
One of the trickiest presentations is amelanotic melanoma, which lacks the dark pigmentation people associate with skin cancer. Instead of a dark or multicolored spot, it appears as a pink or red patch on the skin. Because it doesn’t trigger the usual “suspicious mole” alarm, it’s more likely to be dismissed as a rash or irritation. If you have a pink or reddish spot that persists, grows, or doesn’t respond to normal skin care, it’s worth getting a closer look.
How Skin Cancer Differs on Darker Skin
Skin cancer in people with darker skin tones often shows up in locations that get little sun exposure, which is the opposite of what most people expect. The most common form of melanoma in people with dark skin is acral lentiginous melanoma, which develops on the palms, soles of the feet, fingers, toes, and under the nails.
Under a fingernail or toenail, it looks like a dark band or streak running the length of the nail. If that dark band starts to widen or the pigment begins spreading onto the surrounding skin, that’s a red flag. On the palms or soles, it can appear as a dark patch that may be mistaken for a bruise or discoloration. These areas are easy to overlook during routine skin checks, so they deserve deliberate attention.
What a Skin Check Actually Involves
There’s no universal agreement on how often healthy adults should get professional skin exams. The U.S. Preventive Services Task Force has concluded there isn’t enough evidence to recommend for or against routine screening in the general population, leaving the decision to individual clinicians based on a patient’s risk factors. People with a history of severe sunburns, a family history of melanoma, many moles, or fair skin that burns easily are generally considered higher risk.
Self-checks at home are straightforward. You’re looking at your entire body, including the scalp, between toes, under nails, and on the soles of your feet, for anything new or changing. A mirror or a partner helps for hard-to-see areas like your back. The goal isn’t to diagnose anything yourself. It’s to notice when something appears, grows, or changes so you can bring it to a dermatologist’s attention while it’s still early and most treatable.