Prolonged or repeated exposure to ultraviolet (UV) radiation---from either the sun or tanning bed lights---can increase the risk of developing skin cancer. There are three major types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma. Over 1 million people are diagnosed with these forms of skin cancer each year, reports the American Academy of Family Physicians. Patients who develop any of the common signs of skin cancer should seek additional evaluation and treatment from a medical provider.
Asymmetrical Skin Lesion
An asymmetrical skin lesion or mole can be a sign of skin cancer, warns the National Institutes of Health. The term asymmetrical means that one half of the mole looks different than the other half of the mole. These cancerous skin lesions can have irregular borders and may be rough or scaly to the touch.
Discolored Skin Lesion
An unusual or discolored skin lesion is a common sign of skin cancer in patients. The skin lesions may be darker or lighter than the surrounding skin, explains the American Academy of Family Physicians. Cancerous skin lesions can be unevenly or uniquely colored, and may appear as blue, white, purple or red marks across the affected skin.
Elevated Skin Lesion
Cancerous skin growths can protrude from the skin and may result in the appearance of small, elevated lumps across skin, reports the Environmental Protection Agency. These skin lesions can be firm to the touch and may form a crusty coating that cracks or bleeds, according to the National Institutes of Health. Elevated skin lesions that develop as a result of skin cancer may also feel uneven or bumpy when touched.
Large Skin Lesion
A skin lesion or mole that has a diameter that is larger than 1/4 inch---about the size of an eraser on a pencil---can be indicative of skin cancer, reports the American Academy of Family Physicians. A patient may also have skin cancer if a pre-existing skin lesion suddenly becomes larger.
