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Squamous Cell Carcinoma

  • A cancer in the middle and outer skin layers caused by ultraviolet (UV) exposure
  • Symptoms include raised growths that do not heal or go away on their own
  • Treatments include surgical incision or Mohs surgery
  • Involves dermatologic surgery, dermatopathology, plastic & reconstructive surgery

Squamous Cell Carcinoma


Too many days at the beach without proper sun protection or too much time in a tanning bed can cause significant skin damage, including squamous cell carcinoma (sometimes referred to as SCC).  

The second most common form of skin cancer (after basal cell skin carcinoma), squamous cell carcinoma is on the rise with more than 1 million cases diagnosed each year in the United States. Unlike basal cell cancer, which doesn't spread, squamous cell cancer can spread to the lymph nodes and even to internal organs. 

Yale Medicine's dermatologists are known for their specialized expertise in treating complex skin disorders of all kinds, including skin cancer. "We get referred the cases that need special attention," says David J. Leffell, MD, section chief of Dermatologic Surgery and Cutaneous Oncology at Yale Medicine.. 

What are the risk factors for squamous cell carcinoma?

Squamous cell carcinoma is mainly caused by cumulative ultraviolet (UV) exposure from the sun, according to Dr. Leffell. 

“Daily year-round exposure to the sun’s UV light and intense exposure in the summer months add to the damage that causes this type of cancer,” he says. People at the highest risk for squamous cell carcinoma tend to have light or fair-colored skin; blue, green or gray eyes; a history of sun exposure; and a tendency to sunburn quickly. Squamous cell carcinoma occurs four times more frequently in men than in women.

Although squamous cell carcinoma can be more aggressive than basal cell cancer, the risk of this type of cancer spreading is low—as long as the cancer is treated early, Dr. Leffell says. He notes that the lesions must be treated with respect because they may grow rapidly and invade deeply. While it is more difficult to treat squamous cell carcinoma that has metastasized, up to half of cases can be cured.

In a small percentage of cases, squamous cell carcinoma can grow along the tiny nerves in the skin. In this very serious condition, the squamous cell carcinoma of the face or scalp can travel along the nerves and spread to the brain.

What are the symptoms of squamous cell carcinoma?

Squamous cell carcinomas are usually raised growths, ranging from the size of a pea to the size of a chestnut. They may appear as scaly red patches, open sores or protruding growths with a dented center, or they may look like a wart. 

Most are found in areas of the body that are frequently exposed to the sun, such as the ears, lips, face, balding scalp, neck, hands, arms, and legs. Less commonly, they may appear on mucous membranes and genitals. Regardless of what form the bumps take, they do not heal or go away on their own. 

How is squamous cell carcinoma diagnosed?

Squamous cell carcinoma is diagnosed by a skin biopsy. While the dermatologist may have a good idea of what a skin abnormality is just by looking at it, the main differences between squamous cell and basal cell cancer are apparent under a microscope. 

How is squamous cell carcinoma treated?

Although squamous cell carcinomas usually grow slowly, it is important to see a dermatologist quickly. "The sooner you see your doctor and the cancer is diagnosed and treated, the less complicated the surgery to remove it will be, and the faster you will make a complete recovery,” Dr. Leffell explains. The treatment for squamous cell cancer varies according to the size and location of the lesion. The surgical options are the same as those for basal cell cancer: 

  • Surgical excision: Removing a squamous cell lesion is a simple procedure that typically takes place in the dermatologist's office. After numbing the cancer and the area around it with a local anesthetic, the doctor uses a scalpel to remove the tumor and some of the surrounding skin to make sure all cancer is eliminated. Estimating how much to take requires skill and expertise, Dr. Leffell notes. The risk of taking too little tissue is that some cancer remains; taking too much leaves a larger scar than is necessary. Shaped like a football, the wound is stitched together, using plastic surgery techniques. If dissolvable stitches are used, they will disappear on their own as the area heals. Though the procedure leaves some redness and a small scar, it tends to become less noticeable over time. "The cure rate for this type of excision is typically about 90 to 93 percent," says Dr. Leffell. “But, of course, this is dependent on the skill and experience of the doctor."
  • Mohs surgery: The most thorough method for treating squamous cell cancer is Mohs surgery. This type of surgery is often used when the cancer is on the face, for spots larger than one centimeter, for recurrent cases, or when the doctor cannot easily tell the margins of the cancer. Performed on an outpatient basis, usually in the dermatologist's office, the Mohs method removes the cancer layer by layer. The tissue is checked under the microscope until the doctor is able to confirm that all cancer cells have been removed. Mohs surgery allows the surgeon to be more precise without affecting any more of the normal skin than is necessary. The cure rate for Mohs surgery is about 98-to-99 percent.

What makes Yale Medicine’s approach to squamous cell carcinoma unique?

Simple, small cancers can often be treated very well by a local dermatologist, according to Dr. Leffell. “We rarely see the small cancers. We get referred to the cases that need special attention.”   

Dr. Leffell emphasizes that at Yale Medicine, the patient always comes first. “We like to have a discussion with the patient about what happens after the skin cancer is removed,” he says. “We talk about what's involved with plastic surgery and what's involved with letting the area heal naturally. We prefer to take a minimalist approach and let the patient decide what they want us to do and how they want to let their skin heal.”

“If the decision is made to repair the wound using plastic surgery, we do that immediately in the office setting,” Dr. Leffell says. “Alternatively, allowing the wound to heal naturally is often a great option, and does not rule out doing plastic surgery down the road if needed, though that is very rarely the case.”