Basal Cell Carcinoma (BCC)

What basal cell carcinoma looks like

BCCs vary in appearance. Common types:

Common features: it grows slowly over months to years, may itch or bleed with minor trauma such as drying with a towel, and often seems to heal before returning. It is usually painless.

Causes and risk factors

BCC is caused mainly by ultraviolet (UV) radiation damaging the DNA of basal cells, both from long-term sun exposure and from intermittent intense exposure with sunburns, especially in childhood. Risk factors include:

• Fair skin, light eyes and hair, and skin that burns easily
• Older age, though BCC is increasingly seen in younger adults
• Lots of sun exposure from outdoor work, hobbies or living in sunny climates
• Indoor tanning
• A previous BCC or other skin cancer: about 4 in 10 people who have one BCC develop another within 5 years
• Weakened immune system, especially after organ transplant
• Radiation therapy and arsenic exposure
• Genetic syndromes, such as Gorlin syndrome (basal cell nevus syndrome), which causes many BCCs from a young age

How BCC differs from other skin cancers

Actinic keratoses, rough scaly spots from sun damage, are precancerous for squamous cell carcinoma, not BCC, but they show the skin has significant sun damage.

Diagnosis

A dermatologist examines the lesion, often with a dermatoscope, a handheld magnifier with light that shows characteristic features such as branching blood vessels. They also check the rest of your skin.

A skin biopsy confirms the diagnosis and the subtype. Usually a small shave or punch biopsy is taken under local anesthetic. Imaging (CT or MRI) is only needed for large, deep or recurrent tumors near important structures.

Treatment

The choice depends on the BCC's size, subtype, location, whether it has come back, and your health and preferences.

Surgery

• Surgical excision: cutting out the tumor with a margin of healthy skin, then stitching. Cure rates are very high for low-risk BCCs.
• Mohs micrographic surgery: the surgeon removes the tumor in thin layers and checks each under the microscope during the procedure until no cancer remains. It has the highest cure rate and spares healthy tissue. It is preferred for BCCs on the face, ears, eyelids and lips, large or poorly defined tumors, and recurrent BCC.
• Curettage and electrodesiccation: scraping out the tumor and burning the base. Used for small, low-risk BCCs on the trunk and limbs.

Non-surgical options

• Topical creams: imiquimod or 5-fluorouracil for superficial BCCs. They cause redness and crusting during treatment.
• Cryotherapy: freezing with liquid nitrogen for small superficial BCCs.
• Photodynamic therapy: a light-sensitizing cream activated by light, for superficial BCCs.
• Radiation therapy: for people who cannot have surgery, or after surgery if margins are not clear.

Advanced BCC

For the rare BCCs that are locally advanced or spread, hedgehog pathway inhibitors (vismodegib or sonidegib) taken as tablets, and immunotherapy with cemiplimab, are options.

Outlook

With treatment, more than 95 percent of BCCs are cured. Metastasis is very rare. The main risks are recurrence of the treated tumor and new BCCs elsewhere. Neglected BCCs can grow deep into skin, cartilage and bone, especially near the eyes, nose and ears, causing disfigurement.

Follow-up and prevention

After a BCC, have a full skin check at least once a year, or as your dermatologist advises, and check your own skin monthly.

• Seek shade, especially between 10 a.m. and 4 p.m.
• Use broad-spectrum sunscreen of SPF 30 or higher on exposed skin, reapplied every 2 hours and after swimming or sweating.
• Wear a wide-brimmed hat, sunglasses and protective clothing.
• Avoid tanning beds.
• Protect children from sunburn.
• In high-risk people, a dermatologist may recommend nicotinamide (vitamin B3) to reduce new skin cancers.

Frequently asked questions

What does basal cell carcinoma look like?

BCC often looks like a shiny, pearly or pink bump with tiny visible blood vessels, a flat pink scaly patch, a white waxy scar-like area, or a sore that bleeds, crusts and heals but keeps coming back. It is usually on sun-exposed areas such as the face, ears, neck and shoulders.

Is basal cell carcinoma dangerous?

BCC is rarely life-threatening because it almost never spreads to other parts of the body. However, it keeps growing if untreated and can invade and damage surrounding skin, cartilage and bone, especially on the face. Early treatment is simple and usually curative.

How is basal cell carcinoma treated?

Most BCCs are removed surgically, by excision, Mohs surgery or scraping and burning. Superficial BCCs can be treated with creams, freezing or photodynamic therapy. Radiation is an option when surgery is not suitable. Rare advanced cases may be treated with targeted tablets or immunotherapy.

Can basal cell carcinoma come back?

Yes. A treated BCC can recur at the same spot, especially larger tumors or those on the face, and many people develop new BCCs elsewhere. Regular skin checks with a dermatologist and monthly self-checks help catch recurrences and new cancers early.

What is Mohs surgery?

Mohs surgery removes skin cancer in thin layers, examining each layer under a microscope during the operation until no cancer cells remain. It offers the highest cure rate while preserving as much healthy skin as possible, so it is often used for BCCs on the face and for recurrent tumors.