What is squamous cell carcinoma of the skin?
Squamous cells are found throughout the human body. These cells line organs, such as the lungs, throat, and thyroid. We also have squamous cells in our skin.
The job of squamous cells is to protect what lies beneath. In our skin, these cells sit near the surface, protecting the tissue beneath.
Anywhere we have squamous cells, we can develop a type of cancer called squamous cell carcinoma (SCC).
In the skin, this cancer is usually not life-threatening. It tends to grow slowly, but it can grow deep. When the cancer grows deep, it can injure nerves, blood vessels, and anything else in its path. As the cancer cells pile up, a large tumor can form.
Most people who develop this skin cancer have fair skin that they seldom protected with sunscreen or sun-protective clothing. Before developing this skin cancer, they tend to notice signs of sun damage on their skin, such as age spots, patches of discolored skin, and deep wrinkles.
Anyone can develop squamous cell carcinoma
While anyone can develop this skin cancer, you have a greater risk if you live with a transplanted organ, use(d) tanning beds, or have fair skin that you seldom protected from the sun.
Another sign of sun-damaged skin is having one or more pre-cancerous growths on your skin called actinic keratoses (AKs). Some AKs progress, turning into squamous cell carcinoma (SCC) of the skin.
Although SCC is most common in people who have fair skin, people of all colors get this skin cancer. In people who have skin of color, SCC tends to develop in areas that get little or no sun, such as the mouth, genitals, or anus. It’s believed that the cause of the skin cancer in these areas may be an injury or human papillomavirus (HPV) infection.
Whether the cause is sunlight, tanning beds, injury, or an HPV infection, this skin cancer can show up on the skin in various ways, such as a non-healing sore or patch of rough skin.
What are the signs and symptoms of squamous cell carcinoma?
On the skin, squamous cell carcinoma (SCC) can show up in many ways. You may see one of the following on your skin:
Rough, reddish scaly patch
Open sore (often with a raised border)
Brown spot that looks like an age spot
Firm, dome-shaped growth
Wart-like growth
Tiny, rhinoceros-shaped horn growing from your skin
Sore developing in an old scar
No matter what it looks like, SCC often appears on skin that’s gotten lots of sun, such as the face, lips, bald scalp, ears, or hands. It tends to develop on skin that’s been badly damaged by the sun or indoor tanning. Signs that your skin has been damaged, include age spots, discolored skin, loss of firmness, and deep wrinkles.
Pictures of squamous cell carcinoma on the skin
The following pictures show many of the ways that SCC can appear on the skin.
Rough-feeling, reddish patch
This is an early sign of squamous cell carcinoma.
Round growth with raised borders
This squamous cell carcinoma developed from a pre-cancerous growth called an actinic keratosis.
A sore that won't heal or heals and returns
On the skin or lips, squamous cell carcinoma can look like a sore.
Age spot
This can be a sign of squamous cell carcinoma, which is why you want a board-certified dermatologist to examine your skin before you treat any age spot.
Raised, round growth
This is a common sign of squamous cell carcinoma of the skin.
Animal's horn
When squamous cell carcinoma looks like this, it tends to grow quickly.
Because this common skin cancer can begin on any part of the body that has squamous cells, it can also develop inside the mouth, on the genitals, inside the anus, or in the tissue beneath a fingernail or toenail.
In these areas, this skin cancer may look like a:
Sore or rough patch (inside your mouth)
Raised, reddish patch (genitals, anus)
Wart-like sore (nail, genitals, anus)
Brown or black line beneath a nail
Sore inside your mouth
This squamous cell carcinoma started inside the mouth and grew to cover a larger area.
Dark streak beneath a nail
Squamous cell carcinoma can look like a brown or black line beneath a nail, as shown here.
When it develops around the nail, it can look like a wart that just won’t go away. If you’ve had a wart around a fingernail (or toenail) for years, it’s time for a dermatologist to examine it.
Disappearing nail
A nail can disappear for many reasons, including an HPV infection, which can cause squamous cell carcinoma.
What color is squamous cell carcinoma skin cancer?
This skin cancer tends to be one color, but the color can vary from one SCC to the next. This cancer may be:
Red or pink (most common)
Brown, black, or show flecks of these colors
Yellowish
White
If the spot is covered with scale, you may see white on top and red or pink beneath.
Does squamous cell carcinoma skin cancer hurt?
Some people notice only a change to their skin, such as a sore that won’t heal or heals and returns.
This skin cancer can also cause symptoms, such as:
Itching
Feeling sore or tender where you have the SCC
Numbness or a pins-and-needles sensation
Any sore, wart, or growth that isn’t healing or heals and returns should be examined by a board-certified dermatologist.
How do people find squamous cell carcinoma cancer on their skin?
Many people find it when they notice a spot, round lump, or scaly patch on their skin that is growing or feels different from the rest of their skin. If you notice such a spot on your skin that is growing, bleeding, or changing in any way, see a board-certified dermatologist. These doctors have the most training and experience in diagnosing skin cancer.
To find skin cancer early, dermatologists recommend that everyone check their own skin with a skin self-exam. This is especially important for people who have a higher risk of developing SCC.
What causes squamous cell carcinoma?
The cause of most squamous cell carcinoma (SCC) of the skin is well known. People usually develop this skin cancer because ultraviolet (UV) light has badly damaged their skin. Most UV light comes from:
The sun
Indoor tanning equipment (such as tanning beds and sunlamps)
Sun exposure without sun protection
Spending time in the sun without protecting your skin from the sun greatly increases your risk of developing squamous cell carcinoma of the skin.
How can UV light cause skin cancer?
Every time UV light hits our skin, it can damage some of the DNA inside our skin’s cells. This happens every time we:
Spend time in the sun without sun protection
Use indoor tanning equipment
The body tries to repair this damage. When the body can no longer repair all the damage, changes called mutations develop in our skin’s cells. The mutated cells, which are cancer cells, can multiple quickly. As these cells pile up, a tumor develops.
When a tumor forms in skin cells called squamous cells, we get SCC of the skin. These cells are found in the outermost layer of our skin, which is called the epidermis. The following picture shows you where these cells live.
When mutations develop in skin cells called squamous cells, we get squamous cell carcinoma of the skin.
Do some people have a higher risk of developing squamous cell carcinoma skin cancer?
Yes. The key risk factors for getting this skin cancer are listed below. A risk factor is anything that increases your risk of developing a disease.
UV-damaged skin caused by the sun or tanning beds. While most people get this skin cancer because the sun’s UV rays damaged their skin, tanning also increase the risk. Using a tanning bed once can increase your risk of developing SCC of the skin by 67%1.
Fair skin, light-colored eyes, or naturally red or blond hair. If you have any of these traits, your skin is more easily damaged by the sun.
Sunburns. If you’ve had blistering sunburns, especially in your youth, you have a higher risk of developing SCC of the skin.
Actinic keratoses (AKs). These are precancerous growths on your skin, which are caused by the sun or indoor tanning. Having an AK increases your risk of developing SCC because an AK can progress and turn into SCC of the skin. While not every AK turns into skin cancer, dermatologists recommend treating AKs to prevent this.
Sunny region. Living in an area that’s warm and gets plenty of sun year-round, such as Florida or California, increases your risk.
High altitude. Living at a high altitude also increases your risk.
Previous skin cancer. Having had skin cancer increases your risk of developing more skin cancers.
Organ-transplant recipient. If you have a transplanted organ, such as a kidney, heart, or lung, you have a significantly increased risk of developing SCC of the skin. Being under a dermatologist’s care can help you manage this increased risk.
HPV infection. This skin cancer can develop under a nail, on the genitals, or inside the anus. Researchers have found that in these areas, the cancer is often accompanied by an HPV (human papillomavirus) infection.
Skin injury, such as a burn. Have you burned your skin badly? If so, you have a higher risk of developing skin cancer on the skin that was burned. Skin cancer can develop in scar tissue that forms after a serious burn or other injury. SCC of the skin is the most common skin cancer that forms where skin has been badly burned. The cancer tends to appear years after the injury.
Exposure to arsenic. People who have levels of arsenic in their drinking water or food have a higher risk of developing SCC of the skin. As many pesticides contain arsenic, people who spend a lot of time around pesticides also have an increased risk.
Cigarette smoking. Some studies suggest that smokers develop this skin cancer at an earlier age than do people who don’t smoke or have never smoked.
HIV. In looking at medical records, Danish researchers found that people who are HIV positive have a higher risk of developing the most common types of skin cancer, including SCC of the skin. In this study, the risk of developing SCC was 5.40% higher in people who were HIV positive than in people who did not have HIV.2
Weakened immune system. Our immune system helps defend against cancer, so when something weakens it, we have a greater risk of developing skin cancer. Some medications, such as those that help prevent the body from rejecting a transplanted organ, weaken the immune system. Diseases such as leukemia, also weaken the immune system.
Xeroderma pigmentosum or similar inherited disease. Some people are born with a medical condition called xeroderma pigmentosum (XP). If you have XP, your body cannot repair any of the damage caused by UV light, so your risk of developing skin cancer skyrockets. It’s estimated that XP can raise the risk of getting skin cancer 10,000-fold.
While having one or more risk factors for SCC of the skin increases your risk of developing it, some people who get this skin cancer don’t seem to have any risk factors. People of all colors get this skin cancer, including people of African, Asian, and Latin descent.
If you find a spot on the skin that is growing, bleeding, or changing in any way, see a board-certified dermatologist to find out what it is.
Squamous cell carcinoma is highly treatable when found early
Found early, a dermatologist can often treat squamous cell carcinoma of the skin cancer in the office.
How do dermatologists diagnose squamous cell carcinoma of the skin?
Because this cancer begins on the skin, it’s possible to find it early when it’s highly treatable.
When you see a board-certified dermatologist, your dermatologist will examine your skin carefully.
If your dermatologist finds a spot on your skin that could be any type of skin cancer, your dermatologist will first numb the area and then remove all (or part) of it. This can be done during an office visit and is called a skin biopsy. This is a simple procedure, which a dermatologist can quickly, safely, and easily perform.
Having a skin biopsy is the only way to know for sure whether you have skin cancer.
What your dermatologist removes will be examined under a high-powered microscope. Your dermatologist or a doctor who has in-depth experience diagnosing skin growths, such as a dermatopathologist, is best qualified to examine the removed tissue under a microscope.
After examining the removed tissue, the doctor writes a biopsy report. Also called a pathology report, this report explains what was seen under the microscope, including whether any skin cancer cells were seen.
If you have squamous cell carcinoma (SCC) of the skin, the report will contain the following information when possible:
Type of SCC
Stage of the cancer
Whether the cancer has any features that make it aggressive
How do dermatologists treat squamous cell carcinoma of the skin?
Most patients are treated with a type of surgery called surgical removal. Your dermatologist or Mohs surgeon can often perform this type of treatment during an office visit.
The following describes what to expect from surgical removal and other treatments for this skin cancer:
Surgical removal: Three types of surgical removal are used to treat this type of skin cancer. All can be performed during an office visit while you remain awake.
Your dermatologist will choose the type of surgical removal you receive, based on where the skin cancer appears on your body, how deeply the cancer has grown, and other considerations.
During surgical removal, your dermatologist cuts out the tumor. When the cancer is caught early, this may be the only treatment you need.
Here's what happens during each type of surgical removal used to treat this skin cancer:
Excision: The area to be treated is first numbed. Next, your dermatologist cuts out the tumor along with an area of normal-looking skin. Removing some normal-looking skin helps to get rid of stray cancer cells.
What your dermatologist removes will be looked at under a high-powered microscope by a specially trained doctor, such as a dermatopathologist or pathologist. If the doctor does not see cancer cells in the normal-looking skin, your treatment is complete.
When cancer cells are found in the normal-looking skin, you need more treatment. Often this means more excision. For some patients, another type of treatment may be more appropriate.Mohs (rhymes with nose) surgery: This surgery is often used to treat SCC skin cancer because many of these cancers develop on the face, neck, or hand. Mohs surgery allows the surgeon to remove the least amount of tissue required to treat the cancer.
During Mohs surgery, you remain awake while the surgeon removes one layer of tissue and then examines it under a microscope. This process continues until the surgeon no longer sees cancer cells.
To learn more about what’s involved in having Mohs surgery and when it’s recommended, go to, What is Mohs surgery?Curettage and electrodesiccation: During this type of surgical removal, your dermatologist first scrapes the tumor from your skin, using a technique called curetting. Next, your dermatologist applies an electrode to destroy remaining cancer cells.
A dermatologist may use this procedure to treat a small SCC that is classified as a low-risk tumor. Dermatologists do not use this surgery to treat skin cancer on areas of the body where hair grows heavily, such as the scalp, a man’s beard area, or an armpit.
Radiation therapy: If surgical removal alone cannot treat the cancer or you cannot have surgical removal, your treatment plan may include radiation treatments.
The different types of radiation therapy used to treat SCC are:
Superficial radiation therapy: Beams of radiation are directed just beneath the skin, which treats only the tumor.
External beam radiation therapy: High-energy beams of radiation are sent into the tumor in order to kill cancer cells.
Brachytherapy (bray-key-ther-uh-pee): Radioactive implants are placed inside (or near) the cancer. Also called internal radiation, this therapy is often used to treat prostate cancer.
Radiation therapy may be given as a second type of treatment when there is a high risk that the cancer will spread. In this case, radiation therapy often follows surgical removal.
If the skin cancer has grown deep or spread, radiation therapy may help a patient feel more comfortable.
Cryosurgery: This treatment involves using an extremely cold substance, such as liquid nitrogen, to destroy the cancer cells. Although seldom used to treat SCC, cryotherapy can be an option when the cancer is caught early, or a patient cannot have any type of surgical removal.
Clinical trial: This is a research study. It helps doctors find better treatments for cancer and other diseases. Patients who participate in a clinical trial do so voluntarily. Your dermatologist may recommend that you consider a clinical trial if the treatment could produce the best results for you.
While your dermatologist may recommend a clinical trial, you make the final decision about whether to participate.
Observation: For some patients, observation may be recommended. Observation means that your dermatologist will watch your cancer over time and only consider treatment if the cancer worsens.
This may be an option for an elderly patient who has a slow-growing SCC.
Palliative care: Rather than treat the cancer, this care offers relief from the symptoms or stress of having cancer.
How is squamous cell carcinoma of the skin treated when it spreads?
When this cancer spreads beyond the skin, it travels to the lymph nodes or other organs. Once it spreads, a patient has advanced cancer.
If you've been diagnosed with advanced SCC, you will be cared for by a team of medical professionals. This team will include oncologists (cancer doctors). Your treatment plan may include one or more of the following:
Surgery: When surgery can remove the cancer and you’re healthy enough to have surgery, this is often the preferred treatment. After surgery, another treatment, such as radiation therapy or chemotherapy, is often given. Adding another treatment helps to kill cancer cells.
Radiation therapy: Radiation can target cancer cells in the skin, lymph nodes, or other areas of the body. When a patient has advanced SCC, radiation therapy is often used along with another treatment.
Immunotherapy: This type of treatment helps strengthen your immune system so that it can fight the cancer. Drugs called immunotherapy medications are given for this purpose.
The U.S. Food and Drug Administration (FDA) has approved one immunotherapy medication for the treatment of advanced SCC of the skin. It’s called cemiplimab-rwlc.
In the clinical trials that led the FDA to approve cemiplimab-rwlc, about half the patients who had advanced SCC of the skin had their tumors shrink. In many patients who had tumor shrinkage, the shrinking lasted 6 months or longer. A few patients had their tumors disappear completely.
Cemiplimab-rwlc is given by an intravenous (IV) infusion, which is also known as an IV drip. The infusion for cemiplimab-rwlc usually takes about 30 minutes. Most patients go to a hospital or cancer treatment center once every 3 weeks to receive this infusion.
Immunotherapy
Patients usually receive immunotherapy medication through infusion therapy, which is also called an IV drip.
Another immunotherapy medication may be more appropriate for you. Pembrolizumab is another such medication given to treat advanced SCC of the skin. In clinical trials, pembrolizumab is showing promise.
Pembrolizumab is also given by IV infusion.
Like all medications, immunotherapy drugs are not right for every patient. Because immunotherapy medication changes the way your immune system works, some side effects from these medications can be serious.
Your doctor can tell you whether immunotherapy medication may be an option for you. If this is an option, you may receive only immunotherapy medication or be given this medication along with other cancer treatment.
Chemotherapy: This treatment can help slow the spreading cancer and relieve symptoms. Sometimes, it shrinks tumors.
There are many different chemotherapy drugs. The ones used to treat advanced SCC are usually given by an IV drip.
Chemotherapy drugs work by killing fast-growing cells in the body. Cancer cells are just one type of cell that grows quickly. Hair cells and cells in your gastrointestinal (GI) tract also grow quickly and can be killed. When chemotherapy kills these cells, patients develop side effects, such as hair loss and nausea.
Other treatments for advanced SCC of the skin: No single treatment is best for everyone who has this advanced cancer. Your medical team will consider your unique needs. Another type of treatment may be recommended.
What is the outlook for someone who has squamous cell carcinoma of the skin?
When found early, this cancer is highly treatable. Left untreated, however, SCC can spread deep into the skin and travel to other parts of the body, making treatment difficult.
While treatment can remove the cancer, it’s important to know that this cancer can return. You also have a greater risk of developing another skin cancer.
Once you’ve had squamous cell carcinoma (SCC) of the skin, you have the following risks:
The cancer can return
Another SCC of the skin can develop
Another type of skin cancer, including melanoma (the most serious skin cancer), can appear
You’ll have these increased risks for the rest of your life. To help patients reduce these risks and find skin cancer early, dermatologists recommend the following to their patients who have had SCC of the skin:
Keep all your dermatology appointments. Your dermatologist will tell you how often to return. During these appointments, your dermatologist will examine your skin and lymph nodes for signs of cancer.
Learn to examine your skin and lymph nodes for signs of cancer, and do these exams as often as your dermatologist recommends. These exams can be lifesaving.
Skin self-exam: How to do
Body mole map
Protect your skin from the sun. Protecting your skin from the sun prevents further damage and may allow your body to repair some of the existing damage, which can reduce your risk of getting another skin cancer. Avoiding the sun after treatment for skin cancer will also help your skin to heal and reduce scarring. For these reasons, dermatologists recommend that you protect your skin from the sun every day, even in winter and on cloudy days. Here’s how you can protect your skin:
Avoid the sun whenever possible.
Protect your skin by wearing sunscreen every single day.
Wear clothing that protects your skin from the sun every day.
Never use a tanning bed or other type of indoor tanning. Indoor tanning is not safer than the sun. In fact, the ultraviolet (UV) radiation from tanning beds and other indoor-tanning equipment tends to be stronger than the UV radiation from the sun. Science had shown that this UV radiation is a carcinogen, meaning it can cause cancer.
Organ-transplant recipients may need medication to help reduce their risk
If you have received an organ, the medication you take to prevent your body from rejecting the organ greatly increases your risk of developing skin cancer. Some patients develop many skin cancers.
If you have already developed many skin cancers, your dermatologist may recommend a medication called acitretin. It can help reduce the number of skin cancers you get.
Vitamins and other supplements not effective for reducing skin cancer
You may have heard that taking vitamin A, selenium, or another supplement can reduce the risk of developing another skin cancer. Researchers have found that these do not reduce the number of skin cancers that people developed.
Some patients develop side effects from taking these supplements. When taken in large doses, vitamin A can cause your skin to turn yellow. Selenium can cause an upset stomach.
The best defense against another skin cancer continues to be sun protection and never using tanning beds.
Learning the signs and symptoms of other skin cancers can help you find them early.