What is squamous cell carcinoma?
Squamous cell carcinoma (SCC) is the second most common type of skin cancer. In the majority of cases, it does not spread to other parts of the body.
SCC’s often look like dry or crusty bumps or spots on the skin that might crack or bleed. These spots usually show up in places that get a lot of sun exposure. But they can also happen on skin with an injury or scarring or anywhere on the body.
SCCs will not get better on their own, but having surgery to remove them will probably cure them.
There are other types of SCCs that form in different parts of the body, like the lung, esophagus, thyroid, or vagina. But those are all different, distinct diseases from squamous cell carcinoma of the skin.
What does a squamous cancer look like?
Many times patients think that the growth is a spider bite. Once we see the lesion it is easy for us to determine that it needs a biopsy to rule out skin cancer. —Dr. William Fix
Squamous cell carcinomas look like spots or bumps on the skin that are usually scaly or crusty. They might crack or bleed, and they’re often painful or tender. They do not go away on their own but instead grow over time. They also may look like a big ulcer (area of open skin) that does not close up by itself.
SCCs often arise in areas of your body that are in the sun a lot, like the face, neck, and hands. Some are caused by the human papilloma virus (HPV), so they can develop in areas where the virus causes warts like the skin on the fingers, toes, genitals, and around the mouth.
SCCs can also show up in or next to places where you have a chronic wound, scarring (like from a burn or lichen sclerosus), or skin inflammation (like in discoid lupus).
- A new bump or mark on the skin that does not go away in a few weeks.
- A crusty or scaly bump.
- Painful or tender.
- Cracking, bleeding, oozing without trauma.
Other symptoms you may have
Less commonly, SCCs may look like:
- Tough, horn-like bumps coming out of the skin (cutaneous horns).
- Wart-like growths (verrucous carcinoma).
- Round lumps with a central depression (keratoacanthoma).
- An open sore/ulcer that doesn’t heal.
Can a squamous cell carcinoma kill you?
All skin cancer cells can spread to other parts of the body but this isn't common. Most cases of SCC can be cured if they're caught early. But if you don't get treatment, it can spread beyond the skin.
Around 2% to 4% of SCCs will spread to lymph nodes, bones, or other tissue. SCCs in people of color are more often diagnosed at a later stage, when they may have had a chance to spread.
If it spreads somewhere like your lymph nodes, that means the cancer may be aggressive and more likely to spread. This is called metastatic disease and it can become life-threatening.
Visit your dermatologist (skin doctor), who will check your skin—both the spot in question and the rest of your body—to make sure you don’t have any other growths.
If they think the spot might be skin cancer, they’ll take a biopsy. This means they’ll cut off a small piece of the skin in the doctor’s office, and then send it to a lab, where it will be examined under a microscope.
Once you’re diagnosed with an SCC, your doctor will determine if further testing and/or imaging is necessary. Most cases do not require any extra imaging or biopsies. In extreme or advanced cases, you may need a CT scan or MRI to assess for extension of the tumor.
Also in advanced cases, your doctor may also have to take a biopsy of your lymph nodes to see if the SCC has spread there. Your dermatologist will refer you to an oncologic surgeon for further imaging or biopsies of the lymph nodes if needed.
Causes of squamous cell carcinoma
The virus that causes warts (HPV) can cause some SCCs. Sometimes patients with numerous SCCs who are immunosuppressed (like transplant patients) may be able to decrease their risk of getting an SCC by getting the HPV vaccination. —Dr. Fix
Squamous cells are a normal skin cell near the epidermis (the top layer of skin). With SCCs, your body grows too many of the cells. Usually it’s because the cells’ DNA has been damaged. That damage comes mainly from sunlight (especially sunburns) but other things can damage it including:
- Other UV light exposure (e.g., tanning beds).
- Ionizing radiation (e.g., working with radiation, or having radiation treatments for an illness).
- Viral infections (e.g., HPV).
- Chemicals (e.g., arsenic).
Also, certain genetic conditions, illnesses that cause skin inflammation or scarring (such as discoid lupus or lichen sclerosus), and medical treatments that suppress the immune system (like treatments after an organ transplant), can increase your risk of SCCs. These illnesses and treatments cause chronic damage to the skin and/or the inability of DNA to repair itself.
Certain people are more likely to develop SCCs, especially if you have:
- Fair skin (pale and burns easily in the sun).
- Light eyes and light hair color.
- Many moles on their body.
- A family history of skin cancer.
- A weakened immune system, like after an organ transplant or if you’re taking immunosuppressant medications or chemotherapy.
- A lot of sun exposure.
- Tanning bed use.
- Smoke cigarettes.
- Been exposed to radiation or chemicals like arsenic.
- A precancerous growth (called actinic, or solar, keratoses).
People of color can get skin cancer, even if they don’t tend to get sunburns.
For Black people, UV light exposure is not the main risk factor for SCCs. The biggest risk factor is chronic scarring or skin inflammation from burns, injuries, radiation therapy, or medical conditions like lupus where the SCCs can occur in areas of the rash.
Treatment of squamous cell carcinoma
The treatment for a SCC will require either cutting the lesion out or burning it off. There will be a small scar. There is no magic salve or cream that will fix it. —Dr. Fix
If the biopsy says you have SCC, you’ll need surgery to remove the growth. The surgery should cure you if the lesion is caught early. There are many types of surgery that can help, depending on the size and location of the growth. Usually, the surgery is done in the doctor’s office and using a local anesthesia, where the doctor uses a shot to numb the skin around the growth.
In some cases, your doctor might also use radiation to treat your SCC.
If testing shows that your cancer has spread to your lymph nodes or other organs, your dermatologist will refer you to a medical or surgical oncologist (a cancer specialist) for more testing and treatment.
Skin cancer surgery
Curettage and Electrodessication: Superficial SCCs that only affect the top layer of the skin can be scraped off with a sharp tool called a curette. The skin beneath is then burned with an electrical tool to lower the chance of the growth coming back. This is a simpler surgery, but the risk of SCC coming back is higher than with other procedures, and it may cause a scar.
Excisional Surgery: Your dermatologist will use a scalpel to cut out the SCC and some of the surrounding skin. This lowers the chances of the SCC coming back. You will require sutures after the cancer is removed. It will cause a scar and mild pain, which usually lasts 1 to 2 days.
Mohs Surgery: SCCs that are large or in sensitive areas like the face, genitals, or hands and feet, may need this special type of surgery. The doctor will remove the tumor layer by layer, and after each layer check to see that all the cancer cells have been removed while you wait in the office. They try to remove as little skin as possible while still making sure cancer cells are completely gone.
This surgery is done in a specialized dermatologist’s office with local anesthesia. There will be a scar after the cancer is removed; however, most surgeons are skilled at minimizing the scar. The pain is usually minimal and lasts for 2 to 3 days after the surgery.
Surgery alternative: If you need a large SCC removed and can’t have surgery because of another medical condition, your doctor might suggest radiation therapy. You will go to another specialist (a radiation oncologist) for this.
After you have been diagnosed with SCC, you are at higher risk of getting another skin cancer. See your dermatologist regularly (at least twice a year) for skin checks.
After any procedure for SCC, follow all care instructions. Your dermatologist will tell you when to make a follow-up appointment.
The best way to prevent SCCs and other skin cancers is to be safe in the sun.
- Stay out of the sun during peak hours, from 10 AM to 4 PM.
- Avoid getting sunburned. Remember that can happen year-round, even on cloudy days.
- Use sunscreen every day. Pick one that blocks both UVA and UVB rays. It should be 30 SPF or higher. Re-apply often as directed on the bottle.
- Wear sun-protective clothing in addition to sunscreen. This can be loose-fitting, dark-colored daily clothes that cover a lot of your body. You can also buy specially-made clothing with an Ultraviolet Protection Factor (UPF) rating of over 30, to shield your skin from UV rays.
- Never use tanning beds. They cause severe damage to your skin cells.
- Black skin can also get SCCs, so seeing your dermatologist for skin checks are important. If you have lupus or burns or chronic scarring, you may be at increased risk of SCC
- If you have fair skin, have a family history of skin cancer, history of tanning bed use, or frequent sunburns, you should see your dermatologist yearly for a skin cancer exam even if you don’t have a family history of skin cancer. If you have a history of skin cancer or have a lot of moles, your dermatologist will likely want to see you for a skin exam more frequently (i.e., 2 to 3 times a year).
Some other ways to protect your skin.
- Check your medicines. Some prescription drugs and over-the-counter preparations drugs make skin more vulnerable to sun damage. These include alpha-hydroxy acids; acne medications such as tretinoin; antidepressants; diuretics; and some antibiotics, antihistamines, and sedatives. Ask your doctor if your medication increases your sun sensitivity.
- Know your history. Light skin and hair, childhood exposure to sunlight, and a family history of skin cancer increase your risk of skin cancer.
- Examine your skin regularly. Use a mirror to help you examine your whole body, including your face (check underneath any facial hair), neck, arms, back, buttocks, legs, feet (including the soles), and under your fingernails and toenails. Use a blow dryer to part your hair so you can examine your scalp. See your doctor immediately if you find any new lesions or suspicious-looking areas.