What is basal cell carcinoma?
Basal cell carcinoma (BCC) is a type of skin cancer that begins in the basal cells. Normal basal cells line the epidermis. They’re the skin cells that replace old cells with new ones. Cancer of the basal cells results in tumors that appear on the skin’s surface. These tumors often look like sores, growths, bumps, scars, or red patches.
While BCC almost never spreads to other places in the body (metastasizes), it can still result in disfigurement. In rare cases, it can spread to other parts of the body. If it does, it can become life-threatening.
BCC is the most common type of skin cancer. Approximately 4 million cases of it are diagnosed in the United States every year.
Almost all BCCs develop on parts of the body frequently exposed to the sun. Tumors can develop on the face, ears, shoulders, neck, scalp, and arms. In very rare cases, tumors develop on areas not often exposed to sunlight.
BCCs are typically painless. The only symptom is the growth or change in the appearance of the skin. There are different types of BCC. Each has a different appearance:
- Pigmented BCC: This type appears as a brown, blue, or black lesion, which often has a translucent and raised border.
- Superficial BCC: This type takes on the appearance of a reddish patch on the skin, which is often flat and scaly. It continues to grow and often has a raised edge. It typically takes on this appearance when on the back or chest.
- Nonulcerative BCC: This type appears as a bump on the skin that is white, skin-colored, or pink. It’s often translucent, with blood vessels underneath that are visible. This is the most common type of BCC. It most commonly appears on the neck, ears, and face. It can rupture, bleed, and scab over.
- Morpheaform BCC: This is the least common type of BCC. It typically resembles a scarlike lesion with a white and waxy appearance and no defined border. This type of carcinoma can indicate a particularly invasive form of BCC, which is more likely to be disfiguring.
- Basosquamous BCC: This type of carcinoma carries traits of both BCC and squamous cell carcinoma, another type of skin cancer. It is extremely rare, but is more likely to metastasize compared with other types of skin cancer.
Skin cancers, including BCC, are primarily caused by long-term sun or ultraviolet (UV) light exposure. These cancers can also be caused by intense occasional exposure often resulting in sunburn.
In rarer cases, other factors can cause BCC. These include:
- exposure to radiation
- exposure to arsenic
- complications from scars, infections, vaccinations, tattoos, and burns
- chronic inflammatory skin conditions
Once diagnosed with BCC, there is a strong likelihood of recurrence.
There are a number of risk factors that can increase the likelihood of developing BCC. Some of these risk factors include:
- having a family history of BCC
- having light skin
- having skin that freckles or burns easily
- having inherited syndromes that cause skin cancer, like disorders of the skin, nervous system, or endocrine glands
- having fair skin, red or blonde hair, or light-colored eyes
- being a man
There are other, nongenetic risk factors. These include:
- age, with increased age correlating with increased risk
- chronic sun exposure
- severe sunburn, especially during childhood
- living in a higher altitude or sunny location
- exposure to radiation therapy
- exposure to arsenic
- taking immunosuppressing drugs, especially after a transplant surgery
The first step in diagnosing BCC will be a visual inspection from a dermatologist. They’ll check your skin head-to-toe to look for any skin growths or discolorations. They’ll also ask about your medical history, including family history of skin cancers.
If your dermatologist finds any discolorations or growths of concern, they’ll take a biopsy of the skin. To do this, they’ll inject a numbing agent into the skin before removing a small sample of the lesion for testing. The biopsy will be viewed under a microscope to look for skin cancer.
Your dermatologist will remove the growth if BCC is found. If you have an aggressive form of BCC, your doctor may take a biopsy of your lymph nodes to check for metastasis.
Treatment for basal cell carcinoma involves removing the growth. Your doctor will recommend a treatment depending on the type of BCC you have, the size of the lesion, and the location of the lesion. Treatment options include:
Curettage and electrodessication
In this procedure, the growth is scraped off with a curette. The tumor site is then burned with an electrocautery needle. It is extremely effective, especially on small lesions, though it may not be as effective on aggressive BCCs or high-risk sites. It can leave a round, white scar. This procedure has a 95 percent success rate.
Your doctor will remove the tumor and surrounding border of normal skin around it with a scalpel. This procedure requires stitches to close the surgical site. This is often used for more advanced BCCs, which are at risk for affecting the surrounding skin. It may leave a small scar. This procedure has a 95 percent success rate.
Mohs micrographic surgery
Your doctor will remove a thin layer of tissue that contains the tumor. The layer of tissue is frozen and then mapped under a microscope. The doctor will then repeat the procedure on the exact location the cancer was present.
This procedure can save healthy tissue, and has the highest cure rate at about 99 percent. It’s often used for large tumors, or tumors in highly visible areas like the face or neck.
Cryosurgery is used for cancers that are thin and don’t extend far into the skin. Your doctor can freeze and kill cancerous cells with liquid nitrogen. This has a risk of nerve damage at the site, which can result in loss of feeling.
No cutting is necessary, though anesthesia may be used. The growth will blister or crust over. Cryosurgery is most often used for BCC and people with bleeding disorders. It has a success rate of between 85 and 90 percent.
BCC treatments are often minor and easy to recover from. Many people will experience some pain at the surgery or excision site as it heals.
Scarring is a common effect of BCC treatment. To lessen the appearance of scars, follow the after-treatment instructions your doctor gives you. These instructions will include:
- Keep the excision site clean.
- Apply over-the-counter ointments like Vaseline and Neosporin multiple times a day to help it heal, and keep it covered with a bandage.
- Keep the wound moist. This will help it heal.
There is a high risk of recurrence of BCC. Take precautions to protect your skin from UV exposure.
The most common complication of basal cell carcinoma is recurrence. BCCs commonly recur, even after successful treatment. In some cases, BCC may reappear in the same place. It can also be disfiguring, especially if not treated promptly.
A diagnosis of BCC increases the chance of developing other types of skin cancer. This includes melanoma, which can metastasize and is the most life-threatening form of skin cancer.
Rare, aggressive forms of BCC can invade the body beyond the skin. It can destroy bone, nerves, and muscles. In rare cases it can metastasize to other parts of the body, including key organs, and become life-threatening.
Avoiding or reducing your exposure to UV light is the best way to prevent BCC. Avoid direct sunlight during the brightest parts of the day and avoid using tanning beds.
Apply sunscreen regularly, even if you’re only going to be outside for a few minutes. Use a sunscreen with SPF 15 or higher. You can also wear lightweight clothing and hats to protect against sun exposure. The exception to this is infants. Newborns should be kept out of the sun when possible. Don’t apply sunscreen to infants under six months.
Early detection of BCC can reduce scarring caused by the removal of a tumor. Get a skin cancer check annually from a dermatologist or primary doctor. You should also examine your skin head-to-toe on a monthly basis. If you notice any skin changes, make an appointment with a doctor.