Skin cancer usually appears as a new or changing spot on the skin, often a bump, sore, or patch that looks different from the skin around it. In many cases it causes no pain at all, which is why visual changes are the most important early warning sign. What it looks like and feels like depends on the type, and the three most common types each have distinct appearances.
How Basal Cell Carcinoma Looks
Basal cell carcinoma is the most common skin cancer, and more than 60% of cases are the nodular subtype. It typically appears as a small, round, flesh-colored or pinkish bump with a pearly or waxy sheen. Tiny blood vessels are often visible on the surface. As the bump grows, it frequently develops a central dip or ulcer while the border stays raised and rolled, almost like a tiny crater with a shiny rim.
These growths are slow, adding roughly half a centimeter over one to two years. They can also show up as flat, pale, scar-like patches (the morpheaform type) that feel firm and waxy. Some contain dark pigment that makes them look blue-black or brown. Basal cell carcinomas are fragile. They bleed easily after shaving or minor bumps, and a sore that bleeds repeatedly or won’t heal after several weeks is one of the most recognizable red flags.
How Squamous Cell Carcinoma Looks
Squamous cell carcinoma tends to appear as a firm bump or a flat sore with a scaly, crusty surface. The bump can be pink, red, brown, or black depending on your skin tone. On the lip, it often starts as a rough, scaly patch that eventually opens into a sore. It can also develop inside the mouth or on top of an old scar.
Unlike basal cell carcinoma’s pearly smoothness, squamous cell growths have a rougher, more textured surface. They grow faster and are more likely to feel tender to the touch, especially as they get larger.
How Melanoma Looks
Melanoma is less common but far more dangerous. The standard checklist for spotting it is the ABCDE rule from the National Cancer Institute:
- Asymmetry: One half of the mole doesn’t match the other.
- Border: The edges are ragged, notched, or blurred rather than smooth.
- Color: The color is uneven, with shades of black, brown, tan, white, gray, red, pink, or blue mixed together.
- 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 weeks or months.
Any single one of these features is worth getting checked. A mole that changes noticeably over a short period is especially concerning, even if it doesn’t tick every box.
What Skin Cancer Feels Like
Most skin cancers don’t cause pain or discomfort in their early stages. That’s part of what makes them easy to overlook. Symptoms like itching, tenderness, and bleeding tend to develop only after a growth has been present for a while and has reached a larger size. When symptoms do appear, they can include a persistent itch over the spot, a sore that oozes or crusts over repeatedly, or bleeding from what seems like a minor scratch. Pain is a later sign and is not something to wait for before taking action.
Skin Cancer on Darker Skin
Skin cancer looks different depending on skin tone, and one type in particular is important to know about. Acral lentiginous melanoma develops on the palms of the hands, soles of the feet, and under fingernails or toenails. It occurs at equal rates across all races and accounts for the majority of melanoma diagnoses in people of color.
On the foot or hand, it starts as a black or brown discoloration that can resemble a bruise or stain but grows over time. Under a nail, it looks like a dark vertical streak running the length of the nail bed, sometimes mistaken for blood or a fungal infection. As it progresses, the nail may crack or break. Because these locations aren’t areas people typically check for cancer, acral lentiginous melanoma is often caught later than other types.
What Happens During Diagnosis
If something on your skin looks suspicious, a doctor will examine it and likely perform a biopsy, which means removing a small sample to look at under a microscope. There are three main approaches. A shave biopsy uses a blade to take a thin layer off the surface; it doesn’t require stitches. A punch biopsy uses a small circular tool to remove a deeper, round core of skin, and usually needs a stitch or two. An excisional biopsy removes the entire growth with a scalpel and also requires stitches. Which one you get depends on the size, location, and depth of the spot.
Results typically come back within a week or two. If the biopsy confirms cancer, the next steps depend on the type and how deep the growth goes.
Why Early Detection Changes Everything
The survival gap between early and late-stage skin cancer is dramatic, especially for melanoma. According to the National Cancer Institute’s SEER database, melanoma caught while still localized has a five-year survival rate of 100%. Once it spreads to nearby lymph nodes, that drops to 76%. If it reaches distant organs, it falls to 34%.
Most melanomas are discovered either by the patient noticing something and bringing it up, or by a doctor spotting it incidentally during a visit for something else. There is currently no universal screening recommendation for people without symptoms or a family history. The U.S. Preventive Services Task Force says the evidence is insufficient to recommend routine visual screening for the general population. That puts the responsibility largely on you to know your own skin, notice changes, and bring them up.
Rarer Types Worth Knowing
Merkel cell carcinoma is uncommon but aggressive. It appears as a painless bump on the skin that grows quickly, often on sun-exposed areas of the face, head, or neck. The bump can look pink, purple, red-brown, or skin-colored, and its two halves often don’t match. What sets Merkel cell apart is its speed. It can grow noticeably over just weeks and spreads to other parts of the body faster than most skin cancers. Any rapidly growing bump, even if it doesn’t hurt, deserves prompt evaluation.
What Causes Skin Cancer at the Cellular Level
Ultraviolet radiation from the sun or tanning beds penetrates into skin cells and directly damages their DNA. UVB rays are the most dangerous because they attack DNA structure head-on, while UVA rays generate molecules called free radicals that cause additional harm. When DNA is damaged, the cell either repairs itself or triggers a built-in self-destruct process to prevent the damage from spreading. If neither of those happens successfully, the cell can develop mutations that allow it to grow uncontrollably. That uncontrolled growth is cancer.
This is why cumulative sun exposure and severe sunburns both increase risk. Every round of UV damage is another opportunity for a repair failure. The mutations can accumulate over years or decades before a visible cancer appears, which is why skin cancers often show up later in life even if your worst sunburns happened as a teenager.