Skin cancer can show up as a new or changing spot on your skin, a sore that won’t heal, a shiny bump, a scaly patch, or a mole that looks different from the rest. The specific symptoms depend on the type of skin cancer, and the three most common types each have distinct warning signs worth learning to recognize.
Melanoma: The ABCDE Warning Signs
Melanoma is the most dangerous form of skin cancer, but it’s also one of the easiest to detect early if you know what to look for. The National Cancer Institute uses the “ABCDE” rule to describe the features of early melanoma:
- Asymmetry: One half of the mole doesn’t match the other half.
- Border: The edges are ragged, notched, or blurred. Pigment may spread into the surrounding skin.
- Color: The mole has uneven color, with shades of black, brown, and tan, or areas 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 mole has changed in size, shape, or color over recent weeks or months.
Early detection makes an enormous difference. The five-year survival rate for melanoma caught while it’s still localized to the skin is essentially 100%. Once it has spread to distant parts of the body, that rate drops to 34%.
Melanoma That Doesn’t Look Like Melanoma
About 5% of melanomas are “amelanotic,” meaning they lack the dark pigment most people associate with skin cancer. These appear as pink or red spots on the skin instead. Because they don’t look like a typical mole, they’re often mistaken for a pimple, scar, or other harmless skin change. This confusion means amelanotic melanomas tend to be diagnosed at a later stage, making them worth knowing about even though they’re uncommon.
Basal Cell Carcinoma
Basal cell carcinoma is the most common skin cancer. It grows slowly and rarely spreads to other parts of the body, but it can cause significant damage to surrounding tissue if left untreated. It typically appears in sun-exposed areas like the face, neck, and arms.
On lighter skin, basal cell carcinoma often looks like a slightly transparent or pearly bump that’s skin-colored or pink. You might notice tiny blood vessels on the surface. On brown and Black skin, it tends to appear as a brown or glossy black bump with a rolled border. The bump may bleed and scab over, then bleed again.
Not all basal cell carcinomas look like bumps, though. Some show up as flat, scaly patches that grow slowly over time, or as white, waxy, scarlike areas without a clearly defined edge. The hallmark to watch for is any growth or sore on the skin that won’t heal.
Squamous Cell Carcinoma
Squamous cell carcinoma is the second most common skin cancer. It can appear as a flat sore with a scaly crust, a firm raised bump, or a wartlike growth. On the lip, it may start as a rough, scaly patch that eventually becomes an open sore. The color can match your skin tone or appear pink, red, brown, or black.
Unlike basal cell carcinoma, squamous cell carcinoma carries a higher risk of spreading if it’s not treated. It can also develop in areas you might not expect, including on old scars or areas of chronic skin inflammation.
What Skin Cancer Feels Like
Skin cancer isn’t always painless. Some lesions itch persistently, and the skin around a growth may feel tender or painful. Spontaneous bleeding, where a spot bleeds without being scratched or injured, is another warning sign. A sore that heals and then reopens repeatedly is a classic red flag across all types of skin cancer.
That said, many skin cancers cause no sensation at all, especially in early stages. Don’t wait for a spot to hurt before paying attention to it.
Symptoms on Darker Skin Tones
Skin cancer in people with darker skin often shows up in locations that get little sun exposure, which can be counterintuitive. 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. It can look like a dark patch on your palm or the bottom of your foot, or a dark band running along a nail.
Squamous cell carcinoma on darker skin can be the same color as the surrounding skin, making it easy to overlook. It may appear as a firm bump, a flat sore, or a scaly patch. Basal cell carcinoma tends to show up as a brown, glossy black, or tan bump with a rolled border. Because skin cancer in darker skin tones is often diagnosed later, it’s worth checking areas like the soles of your feet, between your toes, and your nail beds during self-exams.
Precancerous Spots to Watch
Actinic keratoses are rough, scaly patches caused by years of sun exposure. They aren’t cancer yet, but they can develop into squamous cell carcinoma if left untreated. These spots are often easier to feel than to see. Your skin may feel dry, rough, or sandpapery in a specific area. Some patches feel raw or sensitive, or produce a pricking or burning sensation.
They can be red, tan, pink, skin-colored, brown, or silvery, and range from a tiny dot to about an inch across. If you notice a rough patch that persists for weeks and doesn’t go away on its own, it’s worth having it checked.
Merkel Cell Carcinoma
Merkel cell carcinoma is rare but aggressive. It appears as a firm, painless bump on the skin that grows quickly, often over weeks rather than months. The bump may be pink, purple, red-brown, or match the surrounding skin color, and its two sides typically don’t match each other. Merkel cell carcinoma tends to spread rapidly, so a fast-growing bump anywhere on the skin deserves prompt attention.
How to Check Your Own Skin
A monthly self-exam is the simplest way to catch skin cancer early. Work from head to toe, noting any moles, blemishes, or birthmarks. Use a hand mirror for hard-to-see areas like your back, scalp, and the soles of your feet. Taking photos of existing moles helps you track changes over time, and a small ruler can help you measure spots and notice growth.
Beyond the ABCDE rule, look for the “ugly duckling” sign. If you have many moles or freckles, most of them probably look similar to each other. A spot that stands out from the rest, whether it’s scabbed over, more raised, a different color, or simply looks “off” compared to its neighbors, is worth monitoring closely or getting evaluated. Just like in the childhood story, the one that doesn’t match the others is the one to pay attention to.