What Skin Cancer Looks Like

Would you know a basal cell carcinoma if you saw one, on yourself or someone else? What about an actinic keratosis, a dysplastic nevus, or a squamous cell carcinoma? Here's how to identify potentially troublesome skin spots.

What You'll See:

These precancerous lesions typically form on sun-exposed areas like the face, lips and hands. Rough and wartlike, they're small and develop slowly—many people only notice them by touch, rather than by sight.

What's the Risk? Up to 10 percent of actinic keratoses turn into squamous cell carcinoma if left untreated. A derm can freeze them off; other treatment options include chemical peels and topical chemotherapy (creams or gels applied for several weeks to destroy cancerous or precancerous cells).

What You'll See:

These benign growths can look very similar to melanoma—they're larger than 6 millimeters across, with irregular borders and varying shades of color.

What's the Risk? While these moles are noncancerous (and fairly rare), it's essential to have them checked by a dermatologist since they're hard to distinguish from melanoma. If you have any, be even more vigilant about sun protection: Research suggests that people with dysplastic nevi are at greater risk of developing melanoma.

What You'll See:

There are several forms, including some that are shiny, pink and molelike and others that form open sores. They usually occur on parts of the body exposed to the sun: face, ears, scalp, shoulders, back of the neck, hands, arms and legs.

What's the Risk? With nearly 3 million cases diagnosed in the U.S. each year, it's the most common form of skin cancer. Luckily, it rarely becomes life-threatening. But don't ignore it—if not treated promptly, it can grow into nearby bones and tissue and cause disfiguration.

What You'll See:

Thick, rough scaly patches that can crust or bleed, or open sores. The skin around the cancer often serves as a warning, with wrinkles, pigment changes and freckles signaling sun damage in the area. Like the actinic keratosis lesions that often precede it, squamous cell carcinoma grows in areas that get lots of sun.

What's the Risk? It's the second most common type of skin cancer (around 700,000 new cases annually). About 1.5 percent of U.S. patients die from the disease.

What You'll See:

It typically looks like a birthmark or raised mole; keep the "ABCDE" signs in mind (learn more at health.com/ABCDE). Aggressive and fast-growing, it's the deadliest form of skin cancer.

What's the Risk? Anyone can develop melanoma, which occurs when UV-damaged skin pigment cells multiply rapidly to form malignant, molelike tumors. Unlike other types of skin cancer, it can form with just occasional—but intense—exposure to the sun. When caught and treated early, it's largely curable.