Squamous cell carcinoma (SCC) of the skin is a cancer of the cells that make up most of the top layer of normal skin.
It is the second most common form of skin cancer, and up to 700 000 new cases are diagnosed each year in the United States. Lesions of SCC may grow and cause local damage and deformity to surrounding skin and adjacent tissue and in some cases may spread throughout the body and result in death. Squamous cell carcinoma is mainly caused by long-term exposure to the sun over the course of a lifetime. Risk factors are skin that easily sunburns, a history of long-term sun exposure, and previous skin cancer. Men are twice as likely to have SCC as women. It rarely occurs before age 50 years and is most common after age 70 years. In some patients with abnormal immune systems or patients taking certain medications (including immunosuppressive drugs such as cyclosporine and possibly some antibiotic medications such as voriconazole), SCC may occur more often and grow more rapidly.
While SCC lesions may occur anywhere on the body, the most common locations are in areas that are usually exposed to the sun, such as the ears, face, lower lip, neck, hands, arms, and legs. The lesions can look like scaly red patches, crusted thick nodules, open sores, or warts. They may crust over or bleed easily when bumped. Some SCC lesions are tender, but many are painless.
If your physician suspects SCC, he or she will take a small sample of the skin (skin biopsy) to look at under a microscope.
Squamous cell carcinoma is treated by complete removal of the cancerous tissue. Options include surgical excision or a specialized surgery called Mohs micrographic surgery, which is indicated for certain types of high-risk SCC. While in its very early stage, superficial SCC (SCC in situ) may be treated with local destructive measures or topical chemotherapy, but invasive SCC usually requires surgery.
Patients who have had SCC once are at increased risk of getting it again. The earlier the SCC is found, the easier it is to treat. Practicing sun protection, performing regular skin self-examinations, and having annual skin examinations by your physician are important. The American Academy of Dermatology recommends applying a broad-spectrum sunscreen of at least SPF 30 (sun protection factor 30) to all areas of your body that are not covered by clothing. Apply sunscreen 15 minutes before going outside, and reapply it every 2 hours or after swimming or sweating. Seek shade between the hours of 10:00 am and 2:00 pm, when the sun’s rays are strongest. Wear protective clothing such as long-sleeved shirts and wide-brimmed hats whenever possible.
The Skin Cancer Foundationhttp://www.skincancer.org/skin-cancer-information/squamous-cell-carcinoma
The American Academy of Dermatologyhttp://www.aad.org/dermatology-a-to-z/diseases-and-treatments/q---t/squamous-cell-carcinoma
To find this and previous JAMA Dermatology Patient Pages, go to the Patient Page link on JAMA Dermatology’s website at jamadermatology.com.
Conflict of Interest Disclosures: None reported.
Davis J, Bordeaux J. Squamous Cell Carcinoma. JAMA Dermatol. 2013;149(12):1448. doi:10.1001/jamadermatol.2013.6947