In medicine, squamous cell carcinoma is a form of carcinoma cancer that occurs in many different organs, including the skin, the esophagus, the lungs, and the cervix.

Squamous cell carcinomas account for about 20% of non-melanoma skin cancers, (with basal cell carcinomas accounting for about 80%), but are clinically more significant because of their ability to metastasize. Squamous cell carcinoma is usually developed in the epithelial layer of the skin and sometimes in different mucous membranes of the body. This type of cancer can be seen on the skin, lips, inside the mouth, throat or esophagus. This type of cancer is characterized by red, scaly skin that becomes an open sore.