Squamous cell carcinoma (SCC or SqCC) is a form of skin cancer. Skin cancers fall into two groups, melanoma and non-melanoma; squamous cell carcinoma is a non-melanoma cancer. It is one of the most common cancers in humans and other animals.
Squamous cells are a type of epithelium cell forming the outermost layers of the skin and some organs in the body. Squamous cell carcinoma usually occurs on the skin, especially portions commonly exposed to the Sun, the face, ears, neck, hands, or arm. The main symptom is a growing bump that may have a rough, scaly surface and flat reddish patches. It may also occur inside the body wherever squamous cells are found, including the esophagus, urinary bladder, prostate, lung, vagina, and cervix, among others.
Despite the common name, squamous cell carcinomas arising in different body sites can show tremendous differences in their presenting signs and symptoms, natural history, prognosis, and response to treatment.
Though the use of these terms has been decreasing in the literature, SqCC is still sometimes referred to as "epidermoid carcinoma" and "squamous cell epithelium". During its earliest stages, it is sometimes known as "Bowen's disease".