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Squamous Cell Carcinoma of the Skin

Medically reviewed by Last updated on Feb 15, 2024.

What is Squamous Cell Carcinoma of the Skin?

Harvard Health Publishing

Squamous cells are small, flat skin cells in the outer layer of skin. When these cells become cancerous, they typically develop into flat or raised, rounded skin tumors. Sometimes the skin around the tumors gets red and swollen.

Most cases of squamous cell carcinoma occur in people who have spent lots of time in the sun—especially those with fair skin and blue eyes. Some cases develop on skin that has been injured or exposed to cancer-causing agents. This type of squamous cell cancer can develop on:

People with a weakened immune system are at especially high risk of developing squamous cell cancer. This includes people who:

When it is found early and removed, squamous cell carcinoma causes little skin damage. But if the cancer is not removed when it's small, it can leave a scar. In a small number of cases, the cancer spreads to the lymph nodes and other parts of the body. Squamous cell carcinoma is most likely to spread when it is on the lips, ears, or genitals.


Squamous cell skin carcinoma usually appears as a tiny, painless bump or patch. The skin around it can be red and swollen. The cancer itself can be scaly, crusty, or wartlike. It can have an open sore in the center.

Although squamous cell carcinoma can develop on any part of the body, the most common spots are the:


Your doctor will examine your skin and may remove a small, abnormal piece to be examined in a laboratory. This procedure is called a biopsy. Occasionally, the doctor will remove the entire abnormal area.

In the laboratory, a pathologist will examine the tissue under a microscope to determine if it is a skin cancer. If so, the pathologist will look at the margins (edges) of the specimen. If cancer remains at the margin, you will need another procedure to remove the rest of the cancer.

Expected Duration

Once squamous cell carcinoma develops on the skin, it usually grows slowly. But if it is neglected and grows to more than 2 centimeters across, it is three times more likely to spread than a smaller cancer.


Because squamous cell carcinoma is caused by spending time in the sun, you can take steps to prevent it:

If you take prescription medications and you spend significant time outdoors, ask your doctor if you need to take any extra precautions. Some drugs increase your risk of skin damage. These include certain antibiotics and medications used to treat mental illness, high blood pressure, heart failure, acne, and allergies. Also, some skin-care products contain alpha-hydroxy acids. These chemicals can make your skin more vulnerable to damage from the sun.

If a squamous cell carcinoma develops on your skin, you can limit the damage by detecting the problem early. To do this, examine your skin thoroughly every month or two. Use a mirror to look at your back, shoulders, and other areas you can't easily see.


There are many ways to treat squamous cell carcinoma that has not spread. These include:

Which treatment is best for you? That depends on many factors, including the size and location of the cancer, whether it has returned after previous treatment, your age, and your general health.

Once your treatment is finished, your doctor will schedule regular follow-up skin exams. He or she may want to see you every three months for the first year, for example, and then less often after that.

When To Call a Professional

Call your primary care doctor or a dermatologist (a doctor who specializes in skin problems) if you notice that you have an abnormal bump or patch on your skin, or if you have a sore that does not heal.


In most cases, the outlook is excellent. Over all, 95% to 98% of squamous cell carcinomas can be cured if they are treated early. Once a squamous cell carcinoma has spread beyond the skin, less than half of patients live five years, even with aggressive treatment.

Additional Information

National Cancer Institute (NCI)

American Cancer Society (ACS)

American Academy of Dermatology

The Skin Cancer Foundation


Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.