What is skin cancer? The skin is the largest organ of the body. It provides protection, helps regulate body temperature, and plays a role in sensation. It is also the most common site of cancer. Each year about two million people in the United States are diagnosed with skin cancer (Source: AAD). The most common skin cancers are basal cell carcinoma, squamous cell carcinoma, and melanoma. Basal cell carcinomas are often smooth and shiny, may be skin-toned or slightly darker, and may be raised with a central dimple. Squamous cell carcinomas may also be shiny, but they tend to be scalier and may have flat, reddish patches. The appearance of melanomas is often described as ABCD, where A stands for asymmetrical, B stands for borders, which are often irregular, C stands for color, which may be black, brown, tan, or even blue, red, or white, and D stands for diameter, which is often larger than 6mm. The risk factors for developing any of these three types of skin cancers are similar, and include fair skin and excessive sun exposure. The use of tanning beds also contributes to the development of these cancers. Both basal and squamous cell cancers are usually easily treatable with simple removal and typically do not spread to distant sites (metastasize). Melanoma is a more aggressive and dangerous type of skin cancer. If it is not detected and treated early, melanoma has a high risk of spreading and can be fatal. Skin cancers can be serious. Seek prompt medical care if you notice any suspicious changes in your skin including sores that don’t heal, have a shiny, raised appearance or a scaly appearance, or bleed easily. Prompt medical care should be sought for any skin changes that are asymmetrical, have irregular borders, are changing in appearance or color, or are greater than 6 mm in diameter.