The most common warning sign of skin cancer is a change on the skin, especially a new growth or a sore that doesn't heal. The cancer may start as a small, smooth, shiny, pale or waxy lump. It also may appear as a firm red lump. Sometimes, the lump bleeds or develops a crust.
Both basal and squamous cell cancers are found mainly on areas of the skin that are exposed to the sun — the head, face, neck, hands and arms. But skin cancer can occur anywhere.
An early warning sign of skin cancer is the development of an actinic keratosis, a precancerous skin lesion caused by chronic sun exposure. These lesions are typically pink or red in color and rough or scaly to the touch. They occur on sun-exposed areas of the skin such as the face, scalp, ears, backs of hands or forearms.
Actinic keratoses may start as small, red, flat spots but grow larger and become scaly or thick, if untreated. Sometimes they're easier to feel than to see. There may be multiple lesions next to each other.
Early treatment of actinic keratoses may prevent them from developing into cancer. These precancerous lesions affect more than 10 million Americans. People with one actinic keratosis usually develop more. Up to 1 percent of these lesions can develop into a squamous cell cancer .
Actinic keratoses are most common in people older than 40, but can appear in younger individuals with extensive sun exposure. Because they can turn cancerous, affected areas should be regularly examined and treated by a primary care doctor or dermatologist.
Basal cell carcinoma is the most commonly diagnosed skin cancer. In recent years, there has been an upturn in the diagnoses among young women and the rise is blamed on sunbathing and tanning salons.
Basal cell carcinoma is rarely fatal and doesn't typically spread, but it's important to catch it in the early stages so the surgical removal is as non-invasive as possible. It generally occurs on sun-exposed areas and often looks like pink bumps with the following features:
Squamous cell carcinoma is the second most common skin cancer after basal cell. It's rarely deadly, but may spread or recur if not caught early. It's often found on the head, hands, ears, back of neck and forearms — areas with more sun exposure. Characteristics include:
Reviewed by health care specialists at UCSF Medical Center.