www.onlinedermclinic.com In this tutorial, Chris Schach MD, discusses diagnosis, etiology, and treatment of squamous cell carcinoma. Watch Tutorials given by US Board Certified dermatologists at Onlinedermclinic.com. Key Points *Common skin cancer, forming in the cells of the outer skin layer *Most cases caused by sun exposure, but may be the result of other factors *Consists of scaly, crusted lesions which are tender and slow-growing and may ulcerate Squamous cell carcinoma (SCC) is a common skin cancer, which forms in the squamous cells, which make up the outer layer of skin. The condition typically presents in areas exposed to sun, such as the face, lips, ears hands, arms, and lower legs, though it may develop in other areas. It sometimes develops on mucosal surfaces such as the genitals or mouth. SCC in situ is confined to the epidermis, the outer skin layer. SCCs which are invasive spread to deeper skin layers. The condition typically presents as a scaly, crusted lump or bump, which is tender and slow growing. The lesion may develop sores and ulcerate. Lesions may be any size, from very small, to centimeters in diameter. In a small percentage of cases, SCCs may metastasize, most often when located on the lip, ear, back of hand, or scalp. SCC is most often caused by an accumulation of sun exposure. Other factors which may increase the likelihood of developing the condition include family history, smoking, burns, persistent ulcers, long-term use of immunosuppressants …