Also called squamous cell carcinoma, it is a cancer of keratinocyte cells in the outer layer of the skin.
It is the second most common type of skin cancer.
Squamous cell carcinoma is found on the skin and at the edges of the mucosa. Like basal cell carcinoma, a premalignant lesion can take a long time to become cancerous.
Squamous cell carcinoma occurs in areas exposed to the sun, Typically on the lower lip, face, or the back of the hand. Squamous cell carcinoma rarely metastasizes.
It is more likely to metastasize when found on the lip than the other types.
Carcinomas are also known as non-melanoma skin cancers. A carcinoma is a cancerous tumor of the epithelial tissue, the tissue under the skin.
Epithelial tissue is also present in the digestive tract, blood vessels, and other organs, which means that carcinomas can affect body areas other than the skin.
A rare form of skin cancer also exists called Merkel cell carcinoma.
In most cases, people over the age of 50 are diagnosed with carcinoma. Statistics show that 90 percent of carcinomas occur in people with fair skin.
The types of carcinomas
Health professionals define different carcinomas according to the type of cell they occur.
Basal cell carcinoma
BCC (for its acronym in English) develops in basal cells, which are round skin cells found deep in the epidermis of the skin below the squamous cells.
They form the base layer of the epidermis, which meets the dermis.
BCC is unlikely to spread, but doctors who suspect a person has this type of carcinoma will still refer them for further evaluation.
Squamous cell carcinoma
Squamous cells make up most of the top layer of the skin, which people refer to as the epidermis. These cells are flat and scaled.
Doctors who suspect the SCC will provide a more urgent referral as it is more likely to spread than the BCC.
The SCC is, however, much rarer than the BCC. It is responsible for less than 20 percent of non-melanoma skin cancers.
Causes of squamous cell carcinoma
Exposure to ultraviolet (UV) radiation in sunlight is the leading cause of carcinoma and other skin cancers.
Some people are more sensitive to UV light than others and are more vulnerable to the effects of sunlight in the development of cancer.
Additional UV exposure from sunbeds and UV curing lamps in nail salons, for example, can also increase a person’s risk.
UV radiation can cause DNA damage in skin cells, leading to mutations during cell division and possibly skin cancer.
Factors and characteristics that increase carcinoma risk include a personal history of skin cancer and radiation treatment for any cancer, particularly in childhood.
A family history of cancer could also contribute.
Other risk factors include:
- I was having numerous large or irregular moles or freckles.
- A tendency to burn out before taking a tan.
- Have fair skin, blue or green eyes, or blonde, red, or light brown hair.
- Autoimmune diseases, such as systemic lupus erythematosus.
- Hereditary conditions, such as xeroderma pigmentosum syndrome and nevoid basal cell carcinoma, also known as Gorlin syndrome.
- A weakened immune system, possibly due to HIV, receiving an organ transplant, or taking immunosuppressive medications.
- Taking medications that make the skin photosensitive, such as vandetanib (Caprelsa), vemurafenib (Zelboraf), and voriconazole (Vfend).
- Human papillomavirus (HPV) infection, particularly in people with a weakened immune system.
Actinic keratosis, which consists of raised, rough growths that cause precancerous changes in skin cells, is a risk factor that is specific to SCC.
These growths are the most common type of precancerous skin lesion. Without treatment, this condition can turn into skin cancer.
While UV radiation is the leading risk factor for SCC, the following damage to the skin can also increase the risk of this type of carcinoma:
- Skin burns.
- Chemical damage
- Exposure to X-ray radiation.
BCC could also develop after exposure to X-ray radiation in childhood, although this is a much less common cause of carcinoma than UV exposure.
BCC and SCC are skin tumors and share some characteristics. However, these skin lesions can vary in appearance.
Some carcinomas retain a flat surface and, as a result, can resemble healthy skin.
Anyone with an unexpected injury should visit a healthcare professional for a check-up and monitoring.
Aside from its presence, a lump or injury often doesn’t cause noticeable symptoms in its early stages.
As a result, it may not be noticeable until it becomes relatively large, when it may itch, bleed, or cause pain.
Basal cell carcinoma
BCC typically presents as a shiny abscess, a small red or pink lump that grows slowly.
After a few months or years, a shiny, pearly, or waxy-looking edge may form.
A raised rim often sounds like a central ulcer, and abnormal-looking blood vessels can become visible.
These can emerge as blue, brown, or black areas. Alternatively, they can be pinkish growths or pale or yellow spots that look like scars.
Due to this wide range of aspects, obtaining an accurate diagnosis from a doctor is essential.
BCC may appear scaly and often causes recurrent scabbing or bleeding. It may resemble a healing scab when a scab forms, but sores can still occur.
People with BCC often seek medical advice when they discover an ulcer that fails to heal.
Squamous cell carcinoma
SCC usually presents as persistent, thick, rough, scaly patches or a firm pinkish bump with a flat, crusty surface.
These injuries can bleed if someone hits, scratches, or scrapes them. While they sometimes look like warts, they can also appear as open sores with a crusted surface or raised edge.
It is vital to seek the opinion of a healthcare professional regarding the development of new growths or any changes to pre-existing skin growths or sores.
The diagnosis of skin cancer requires a physical exam and a biopsy.
To diagnose any form of skin cancer, a doctor will perform a physical exam. They will examine the skin lesion and record its size, shape, texture, and other physical attributes.
They can also take a photo of the injury for a specialized review or to record its current size and appearance for future comparison. The doctor will often check the rest of the body for additional skin symptoms.
They will also take a medical history focused on the injury and any related conditions, such as sunburn.
A physician will urgently refer suspected cases of SCC for specialized investigation and treatment due to its tendency to spread. Tumors suspected of BCC do not require such an urgent referral, as they are less likely to spread.
If they think a lesion may be cancerous, the doctor will likely perform a biopsy. There are four different types of skin biopsy, all of which involve the removal of tissue from the skin for laboratory evaluation.
The different types are:
Shave biopsy: Using a sharp surgical blade, the doctor shaves the upper layers of skin cells, usually down to the dermis, but sometimes more profound. This type of biopsy often results in bleeding, but it can be stopped by cauterizing the wound.
Needle biopsy: The doctor uses a sharp, hollow surgical tool that resembles a cookie cutter to remove a circle of skin from under the dermis. A person may need a single stitch to close the resulting wound.
Incisional biopsy: The doctor removes some of the growth with a scalpel, cutting a wedge or a full-thickness slice of skin. This type of biopsy often needs more than one point later.
Excisional biopsy: The doctor removes all of the growth and some of the surrounding tissue with a scalpel. The resulting wound generally requires stitches.
After taking the tissue sample, the doctor will send it to a pathology lab for examination under a microscope. The pathology team will test the cells for cancerous features. If cancer is present, they will determine its type.
Additional investigations are not usually necessary for people with BCC, as it is rarely spread. However, people with SCC may need to be tested for cancer in other tissues.
Additional tests usually involve imaging and may include:
- CT scans.
- MRI scans.
- Positron emission tomography (PET).
If a doctor diagnoses skin cancer, they will designate it as a stage. To do this, they will assess its size and depth and how it has spread to local and distant sites in the body, such as nearby lymph nodes or other organs.
To help them find cancer, the doctor may also remove tissue from the lymph nodes near the site of the carcinoma. They will often use a fine needle biopsy for a lab test.
Staging may not occur until after the surgical removal of a skin tumor. Stages range from 0 to 4, and 0 represents carcinoma in situ, which affects only the top layer of the skin.
Stage 4 carcinoma refers to a carcinoma spread to other parts of the body. The stages in between describe the lesion’s size, the tissue’s depth, and any nearby invasions.
Squamous cell carcinoma treatment
There are many methods available to remove potentially harmful moles, including cryotherapy.
Treatment options for both types of carcinoma are similar, although the medical team emphasizes monitoring people with SCC for signs of metastasis.
The specific treatment (s) your doctor recommends will depend on the carcinoma’s size, type, stage, and location. The doctor will also consider additional factors, such as possible side effects and the individual’s preference.
Either way, treatment will likely include a team of healthcare professionals, including dermatologists and surgical, medical, and radiologic cancer specialists.
Treatment options may include the following:
Curettage and electrodesiccation is a standard procedure to remove a small lesion. The doctor uses a small, sharp spoon- or a ring-shaped instrument called a curette to scrape off the carcinoma before burning the site with an electric needle.
It may take more than one round of curettage and desiccation to kill cancer cells completely.
Surgical excision: A surgeon removes the lesion, sometimes in a procedure known as Mohs surgery, which works best on larger lesions—the surgeon checks for cancer cells after removing each layer.
Mohs surgery is beneficial in cases that require the removal of as little skin as possible, such as injuries near the eye. Doctors will also use it on wounds with a high risk of recurrence.
Cryosurgery: For small tumors, doctors may use this procedure, which involves the application of liquid nitrogen to freeze and kill cancer cells. The lesion then blisters and falls off in the weeks after treatment.
Topical chemotherapy: The doctor may apply chemicals or drugs that kill cancer cells directly to the skin.
The chemotherapy option is 5-fluorouracil, including Carac, Efudex, Fluoroplex, and other drugs. A doctor may apply this anticancer drug to the skin once or twice a day for several weeks.
Because this local treatment does not reach other systems in the body, it does not cause the side effects that often occur with chemotherapy for different types of cancer.
Non-chemotherapeutic treatment options include imiquimod cream, which is available under Aldara and Zyclara.
This cream is sufficient for small CCBs, and it works by stimulating the body to produce interferon, which causes the immune system to attack the tumor.
A doctor can also inject interferon directly into the injury.
Radiation therapy: The treatment team targets large or difficult to remove lesions with focused radiation.
Photodynamic Therapy (PDT): Doctors sometimes use this two-step therapy to treat BCC. They will apply a light-sensitive cream to the affected area of the skin and then expose it to a vital light source.
Light has a particular wavelength of blue light, which leads to the death of carcinoma cells.
Since the skin remains sensitive to light for the next 48 hours, people should avoid UV light to minimize the risk of severe sunburn.
Laser therapy for carcinoma: involves the use of different types of lasers to kill cancer cells. Some lasers vaporize or remove the top layer of the skin, destroying any lesions present there.
Other lasers are non-ablative and penetrate the skin without removing the top layer. There is some evidence of its success in treating small and superficial CCBs.
The United States Food and Drug Administration (FDA) has not yet approved laser therapy for BCC. However, doctors can sometimes use it as secondary therapy if other treatments have not been successful.
There is currently no routine screening program available for carcinoma. Instead, people can examine themselves for suspicious injuries or ask a doctor for a physical exam.
The main risk factor for both types of carcinoma is UV light. The best prevention strategy is to adopt sensible practices regarding sun exposure and avoid tanning beds.
Minimize Sun Exposure – By reducing their exposure to UV light, people can reduce the risk of sunburn, skin damage, and all types of skin cancer, including carcinoma.
Although some sun exposure is necessary to maintain healthy vitamin D levels, which is vital for supporting skin health, sunburn increases the risk of carcinoma.
People can reduce sun exposure by seeking shade when the sun is at the peak, usually between 10 a.m. and 4 p.m.
Clothing: Clothing that protects the skin from the sun includes wide-brimmed or peaked hats, shirts with sleeves, and sunglasses.
Clothing in sunscreen fabrics must have labels showing a UV 400 or UV protection factor (UPF). For best protection, choose loose-weft materials.
When shopping for sunglasses, check the labels for a statement of 100 percent protection against UVA and UVB radiation.
Approved Broad Spectrum Sunscreens – Choose an effective sunscreen and apply it generously and regularly to your skin to block UV light exposure.
Check the label to ensure the sunscreen protects against UVA and UVB radiation.
Since some sunscreens are ineffective and contain substances suspected of causing cancer, check consumer reports to ensure that a particular brand of sunscreen is safe and effective before using it.
Use a sunscreen with a sun protection factor (SPF) of at least 30 and reapply to all exposed skin every 2 hours. Increase application once an hour after heavy sweating or swimming. Waterproof lotions are also available.
Babies and young children are particularly vulnerable to sun exposure. People should also be aware that UV light levels are more dangerous at higher altitudes, in places closer to the equator, and sunny locations throughout the year.
The US Preventive Services Task Force states that children, adolescents, and young adults ages 10-24 with fair skin should minimize exposure to UV radiation.
Avoid tanning beds – Tanning beds, tanning rooms, and sunlamps significantly increase carcinoma risk.
Artificial tanning is more dangerous than natural sunbathing because it exposes the body to a concentrated source of UV radiation. Avoid using nail lamps when receiving a manicure or pedicure, as they could also increase your risk of skin cancer.
This tip is especially relevant for people who receive regular nail treatments.
Self-exam is vital to identify moles and lesions that could turn into skin cancer.
The basic principle of detecting carcinoma and other forms of skin cancer is to look for changes in the skin that do not resolve.
To be effective, the skin self-exam must include:
- Pay particular attention to areas of the skin that receive a lot of sun exposure.
- Ask a partner or family member to check hard-to-see neighborhoods and use full-length and hand-held mirrors.
- Knowing your skin and learning how moles and marks generally seek to recognize any changes.
- Take photos, which can help track changes.
- Checking for differences in size, shape, color, or texture.
- Perform self-examination in good lighting.
- Seek medical attention for sores that do not heal.
- Work your entire body systematically from head to toe to examine all areas.
- Check all areas of the body, including the most intimate.
- Keep a note of any observations and record the dates of the self-exams.
These measures can help people find carcinomas early and treat them before spreading.
Treatment is likely to be most effective in cases where a person identifies skin changes early and receives immediate medical attention.
In cases where cancer is responsible for skin changes, early treatment dramatically improves the chance of survival and reduces the likelihood of significant tissue trauma and disfigurement.
BCC has an excellent survival rate, as it rarely spreads beyond the original site. Doctors can often treat it in the office.
SCC can be treated in its early stages, and most treatments are more than 90 percent effective. Mohs surgery is the most effective option, resolving SCC in 97 percent of people who receive this treatment.
However, if the SCC spreads beyond the original site and reaches other systems in the body, the survival rate drops to around 30 percent.