Squamous cell carcinoma is one of the most common types of skin cancer. It can arise in a pre-exisiting actinic keratosis or can begin without warning, but usually this type of cancer is found on excessively sun-damaged skin. Squamous cell carcinoma is also seen on skin that has been exposed to radiation treatments or in burn scars or other areas of scarring. Untreated, it can penetrate and destroy underlying tissue and in a small number of cases it can spread to lymph nodes and other organs. Squamous cell carcinomas appear usually as a thickened scaly or raised growth but can mimic the appearance of a wart or an open, bleeding sore. They are much more common in people with fair skin, light hair and eyes. Early surgical removal of squamous cell carcinomas results in a cure rate of 95%.