Skin cancers show up in surprisingly different ways depending on the type, from shiny translucent bumps to flat scaly patches to dark streaks under a fingernail. There is no single “look” for skin cancer, which is exactly why knowing the specific visual patterns matters. The three main types, basal cell carcinoma, squamous cell carcinoma, and melanoma, each have distinct features you can learn to recognize on your own skin.
Basal Cell Carcinoma
Basal cell carcinoma is the most common skin cancer, and it often looks like a slightly transparent bump on the skin. On lighter skin, it appears pearly white or pink with a translucent quality, almost like you can see slightly through the surface. Tiny blood vessels are sometimes visible on or around the bump. On brown and Black skin, the same cancer looks quite different: a brown or glossy black bump with a rolled, raised border.
Not all basal cell carcinomas look like bumps, though. They can also appear as a flat, scaly patch with or without a raised edge, a brown or blue lesion with dark spots and a translucent border, or a white, waxy, scar-like area without a clearly defined border. One hallmark behavior is a bump that bleeds, scabs over, and then seems to heal, only to bleed again. A sore that keeps cycling through bleeding and scabbing for more than a week or two without fully healing is a red flag worth getting checked.
Squamous Cell Carcinoma
Squamous cell carcinoma tends to look rougher and more textured than basal cell. It commonly appears as a firm nodule on the skin or a flat sore topped with a scaly crust. The color varies widely: it can match your natural skin tone or show up as pink, red, brown, or black. A rough, scaly patch on the lip that eventually breaks open into a sore is a classic presentation, and sores or rough patches inside the mouth can also be squamous cell.
One pattern to watch for is a new sore or raised area developing on top of an old scar or wound. Squamous cell carcinoma can also appear as a wart-like growth. These lesions are most common on areas that get regular sun exposure, like the face, ears, hands, and forearms, but they can develop anywhere on the body.
How Melanoma Looks Different
Melanoma is the most dangerous common skin cancer, and its visual features are distinct enough that doctors use a specific checklist called the ABCDE criteria to evaluate suspicious spots:
- Asymmetry: One half of the mole doesn’t match the other.
- Border: The edges are irregular, ragged, or blurred rather than smooth and round.
- Color: The color is uneven. You might see shades of brown, black, and tan mixed together, or patches of white, gray, red, pink, or blue within the same spot.
- Diameter: Most melanomas are larger than 6 millimeters across (about the size of a pencil eraser), though they can be smaller when first developing.
- Evolving: The spot is changing in size, shape, or color over weeks or months.
Melanoma’s color variety is one of its most telling features. A normal mole is typically one uniform shade of brown. A melanoma often contains two, three, or more colors swirled together. Any mole that develops a new color, particularly blue, black, or red tones, deserves attention.
The Ugly Duckling Sign
Beyond the ABCDE criteria, there’s a simpler and surprisingly effective way to spot a suspicious mole. Most people’s moles share a family resemblance: they tend to be roughly the same size, shape, and color. If one mole looks noticeably different from all the others, that’s what dermatologists call the “ugly duckling” sign. Maybe it’s darker, more raised, scabbed over, or just doesn’t fit the pattern. That outlier is worth showing to a doctor, even if it doesn’t obviously meet every ABCDE criterion.
Skin Cancer on Darker Skin Tones
Skin cancer looks different on melanin-rich skin, and those differences contribute to later diagnoses. Basal cell carcinoma appears as a brown, glossy black, or tan bump with a rolled border rather than the pearly pink bump seen on lighter skin. Squamous cell carcinoma can be the same color as surrounding skin, making it harder to notice. Melanoma on dark skin often presents as a dark or black bump that may look waxy or shiny.
The most common form of melanoma in people with dark skin is acral lentiginous melanoma, which develops in places that don’t get much sun at all: the palms, soles of the feet, fingers, toes, and under the nails. On the palm or sole, it looks like a dark, irregularly shaped patch. Under a nail, it appears as a dark vertical streak running from the base of the nail to the tip, almost like someone drew a line with a brown or black marker. Over time, the streak may widen, become more irregular, or cause the skin around the nail to darken (a warning sign called the Hutchinson sign). The nail itself may lift away from the nail bed, develop a nodule, or start to bleed.
Precancerous Spots
Actinic keratoses are rough, scaly patches caused by years of sun exposure. They’re not cancer yet, but they sit on the path toward squamous cell carcinoma, and doctors sometimes can’t tell the two apart without a biopsy. These patches are typically small, irregular, and feel rough or gritty like sandpaper when you run a finger over them. They’re usually pink, red, or beige and show up on the areas that get the most sun: the face, ears, backs of the hands, and forearms.
In more advanced cases, an actinic keratosis can grow into a hard, cone-shaped horn protruding from the skin surface, sometimes dark or yellowish in color. Any rough, scaly patch that persists for weeks, especially if it’s on sun-exposed skin, is worth having evaluated. Early treatment of these spots can prevent them from progressing.
Rare Types
Merkel cell carcinoma is uncommon but aggressive. It typically appears as a painless, firm bump or nodule on the skin that grows noticeably fast, sometimes doubling in size within weeks. The bump can be red, pink, or purplish, and in some cases it presents as a red, scaly, or ulcerated area rather than a raised nodule. The speed of growth is the distinguishing feature. Most benign skin bumps grow slowly or not at all, so any new nodule that’s visibly expanding over a short period needs prompt evaluation.
How to Check Your Own Skin
A monthly self-exam is the standard recommendation. The best time is right after a shower, in a well-lit room, using a full-length mirror and a handheld mirror for hard-to-see areas like your back, scalp, and behind your ears. Ask a partner or close friend to help with spots you can’t easily see yourself.
Check everywhere, not just sun-exposed skin. That includes your scalp (part your hair in sections), between your toes, the soles of your feet, your palms, your fingernails and toenails, and your genital area. You’re looking for anything new, anything that’s changed, and anything that stands out from its neighbors. A sore that bleeds and doesn’t fully heal within a couple of weeks, a mole that’s shifted in color or size, a shiny bump that wasn’t there before, or a dark streak under a nail that you can’t explain with an injury are all worth noting and showing to a dermatologist.