Squamous cells are found in the upper layer (the surface) of the epidermis. They look like fish scales under a microscope and present as a crusted or scaly patch of skin with an inflamed, red base. They are often tender to the touch. It is estimated that 250,000 new cases of squamous cell carcinoma are diagnosed annually, and that 2,500 of them result in death.
Squamous cell carcinoma can develop anywhere, including inside the mouth and on the genitalia. It most frequently appears on the scalp, face, ears and back of hands. Squamous cell carcinoma tends to develop among fair-skinned, middle-aged and elderly people who have a history of sun exposure. In some cases, it evolves from actinic keratoses, dry scaly lesions that can be flesh-colored, reddish-brown or yellow black, and which appear on skin that is rough or leathery. Actinic keratoses spots are considered to be precancerous.
Like basal cell carcinoma, squamous cell carcinoma is diagnosed via a biopsy — either excisional, where the entire tumor is removed along with some of the surrounding tissue, or incisional, where only a part of the tumor is removed (used primarily for large lesions).
Treatments for basal cell carcinoma include:
- Cryosurgery Some basal cell carcinomas respond to cryosurgery, where liquid nitrogen is used to freeze off the tumor.
- Curettage and Desiccation — The preferred method of dermatologists, this treatment involves using a small metal instrument (called a curette) to scrape out the tumor along with an application of an electric current into the tissue to kill off any remaining cancer cells.
- Mohs Micrographic Surgery — The preferred method for large tumors, Mohs Micrographic Surgery combines removal of cancerous tissue with microscopic review while the surgery takes place. By mapping the diseased tissue layer by layer, less healthy skin is damaged when removing the tumor.
- Prescription Medicated Creams — These creams can be applied at home. They stimulate the body's natural immune system over the course of weeks.
- Radiation Therapy — Radiation therapy is used for difficult-to-treat tumors, either because of their location, severity or persistence.
- Surgical Excision — In this treatment the tumor is surgically removed and stitched up.