The three main types of skin cancer, basal cell carcinoma, squamous cell carcinoma, and melanoma, each have distinct visual signatures. Knowing what to look for on your own skin is one of the most practical things you can do, because catching any of these early changes the outcome dramatically. Here’s what each type actually looks like, including some less common forms that are easy to miss.
Basal Cell Carcinoma
Basal cell carcinoma (BCC) is the most common skin cancer, and it tends to look deceptively minor. The classic presentation is a shiny, pink or flesh-colored bump with a pearly or waxy quality to it. You might notice tiny blood vessels running across the surface, giving it a slightly reddish web-like pattern. As it grows, the center can break down and form a shallow ulcer, while the edges roll up into a raised, rounded border. Dermatologists sometimes call this a “rodent ulcer” because of the way it looks like something has been gnawing at the skin.
BCC is a slow grower, averaging about 0.7 mm per month in lateral spread. That’s roughly the width of a pencil lead each month, which means many people live with one for a long time before realizing it isn’t just a persistent pimple or irritated patch. Some BCCs look like a flat, scaly, reddish area rather than a raised bump, especially on the chest or back. Others resemble a small scar that appeared without any injury. The common thread is that the spot doesn’t heal. If you have a sore or shiny bump that crusts over, bleeds a little, then seems to heal only to open up again weeks later, that cycle of “almost healing” is a hallmark of BCC.
Squamous Cell Carcinoma
Squamous cell carcinoma (SCC) often looks rougher and more textured than BCC. The typical sign is a firm bump or nodule that may be pink, red, brown, or skin-colored depending on your complexion. Many SCCs have a scaly, crusted surface that feels like sandpaper, and they can bleed if the crust is picked off. Some appear as flat sores with a persistent scaly top that never fully resolves.
SCC has a few presentations worth knowing. On the lips, it often starts as a rough, scaly patch that eventually cracks open into a sore. Inside the mouth, it can show up as a raised, rough patch on the gums or inner cheek. On old scars or areas of chronic skin damage, SCC sometimes emerges as a new raised area or sore within tissue that was already compromised. Unlike BCC, SCC can also develop a wart-like texture, especially on the hands, arms, or other sun-exposed areas. The key visual clue is a spot that looks irritated, scaly, or crusty and simply won’t go away over several weeks.
The Precursor: Actinic Keratosis
Many SCCs start as actinic keratoses, which are rough, dry, scaly patches that develop on sun-damaged skin. They can be skin-colored, pink, or tan, and they’re often easier to feel than to see. Running your fingers over sun-exposed areas like the forehead, scalp, ears, and backs of the hands, you might notice a gritty or sandpapery texture before you notice any visible change. Individual actinic keratoses have a low risk of becoming invasive SCC, roughly estimated at about 1% over 10 years per lesion, though some estimates run higher. The issue is that most people with sun damage have several at once, which raises the cumulative risk.
Melanoma and the ABCDE Rule
Melanoma is the least common of the three major skin cancers but the most dangerous. It develops from the pigment-producing cells in your skin and often looks like a mole that has gone wrong. The widely used ABCDE rule captures the visual warning signs:
- Asymmetry: One half of the spot doesn’t mirror the other.
- Border: The edges are ragged, notched, or blurred rather than smooth and round. Pigment may bleed outward into surrounding skin.
- Color: Multiple shades are present in one spot, including mixtures of brown, tan, black, red, white, blue, or gray.
- Diameter: Most melanomas are larger than 6 millimeters across (about the size of a pencil eraser) at diagnosis, though they can be smaller.
- Evolving: The spot has changed in size, shape, color, or feel over recent weeks or months.
Of these, “evolving” is the single most useful signal in practice. A mole you’ve had for 20 years that suddenly starts changing, whether it’s growing, darkening, developing an irregular border, itching, or bleeding, deserves attention even if it doesn’t check every other box. Melanoma can also appear as a brand-new dark spot that looks different from the other moles on your body. Dermatologists call this the “ugly duckling sign”: the one spot that doesn’t look like anything else on your skin.
Melanoma Without the Dark Color
Not all melanomas are dark brown or black. Amelanotic melanomas have little to no pigment and account for roughly 2% to 8% of all melanomas. They can appear as pink, red, or skin-colored bumps or patches that look nothing like what most people picture when they think of skin cancer. Some resemble a small blister-like plaque with well-defined borders. Others look like a smooth, reddish bump that could pass for a pimple or a healing scratch.
Because they lack the telltale dark pigmentation, amelanotic melanomas are frequently confused with basal cell carcinoma, squamous cell carcinoma, and even benign conditions like dermatitis or a wart. This makes them harder to catch early. If you have a pink or red bump that persists for more than a few weeks, doesn’t respond to typical treatments, and doesn’t clearly fit the profile of something harmless, it’s worth having it examined.
Less Common Types Worth Knowing
Merkel Cell Carcinoma
Merkel cell carcinoma is rare but aggressive. It usually appears as a firm, painless, shiny bump that’s pink, red, or bluish-red. What makes it tricky is that it grows fast, often noticeably bigger within just a few months, yet it doesn’t hurt. In a study of 195 patients, 88% of Merkel cell tumors were completely painless despite rapid growth, and 63% of patients reported visible expansion within three months. That combination of “fast-growing but not tender” is actually a useful distinguishing feature. Many things that grow quickly and look red on the skin, like an inflamed cyst, tend to be painful. A rapidly expanding, painless nodule on sun-exposed skin in someone over 50 with fair skin fits the clinical profile closely.
Sebaceous Carcinoma
Sebaceous carcinoma most commonly develops on the eyelid as a small, painless lump that can look pink, red-brown, or yellowish. Because of its location and appearance, it’s often mistaken for a stye or a chalazion (a blocked oil gland). The difference is that a stye typically resolves within a week or two, while sebaceous carcinoma persists and gradually thickens. You might also notice the eyelid skin becoming firmer or more swollen over time. Any eyelid bump that doesn’t clear up after several weeks, or that keeps coming back in the same spot, is worth a closer look.
What Growth Speed Tells You
How quickly a spot changes can help you gauge urgency. Basal cell carcinoma is generally the slowest, expanding less than a millimeter per month on average. You could have a BCC for a year and see it grow only 8 or 9 millimeters total. Squamous cell carcinoma tends to grow somewhat faster, and melanoma varies widely depending on the subtype, but some forms can progress from a small spot to a dangerous depth within months. Merkel cell carcinoma is among the fastest, with visible changes in weeks.
Slow growth does not mean a spot is safe. It means you have more time, not that you can ignore it. And a spot that’s changing quickly, even if it looks like nothing serious, deserves prompt evaluation precisely because the aggressive cancers are often the ones that don’t look like what you’d expect.
Patterns by Location
Where a spot appears can narrow the possibilities. BCC and SCC strongly favor chronically sun-exposed areas: the face, ears, neck, scalp, forearms, and backs of the hands. The nose alone is one of the most common sites for BCC. Melanoma can appear anywhere on the body, including places that rarely see the sun, like the soles of the feet, between the toes, under fingernails or toenails, and on the genitals. A dark streak appearing under a nail, especially one that’s widening or affecting a single digit, is a specific warning sign for a subtype called subungual melanoma.
On the legs, melanoma is more common in women. On the trunk, it’s more common in men. But no body site is exempt, which is why checking your entire skin, not just the spots you can see in a bathroom mirror, matters. The back, the backs of the thighs, and the scalp are easy to miss without a partner or a second mirror.