Carcinoma is a category of types of cancer that develop from epithelial cells. Specifically, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that arises from cells originating in the endodermal, mesodermal or ectodermal germ layer during embryogenesis.

Untreated squamous cell carcinoma of the skin can destroy nearby healthy tissue, spread to the lymph nodes or other organs, and may be fatal, although this is uncommon. The risk of aggressive squamous cell carcinoma of the skin may be increased in cases where the cancer: Is particularly large or deep.Ultraviolet (UV) rays from the sun or from a tanning bed are the main cause of basal cell carcinoma. When UV rays hit your skin, over time, they can damage the DNA in your skin cells. The DNA holds the code for the way these cells grow. Over time, damage to the DNA can cause cancer to form