What is Basal Cell Carcinoma (BCC)? Causes, Symptoms and Treatment

Basal cell carcinoma (BCC) is the most common form of skin cancer in the world, and the number of cases is rising year on year. Fortunately, BCC is also the least aggressive form of skin cancer — and it has a very high cure rate, especially when detected early.

In this article, we explain exactly what BCC is, what it looks like, who is at risk, and what treatment options are available.

What is basal cell carcinoma (BCC)?

Basal cell carcinoma (BCC) — also called basal cell skin cancer — develops from basal cells, which form the lowest layer of the epidermis. These cells sit just above the boundary with the dermis and are responsible for continuously renewing the skin's surface cells.

BCC typically grows slowly over months to years. It rarely spreads to other organs (metastasises), which distinguishes it from more aggressive forms of skin cancer such as melanoma and squamous cell carcinoma (SCC). However, if left untreated, BCC can grow deep into the skin and damage underlying structures such as bone and cartilage — especially on the face.

According to the International Classification of Diseases (ICD-11), BCC is classified as code 2C32 (Basal cell carcinoma of skin).

What does basal cell carcinoma look like?

BCC can appear in several different forms, and it is important to be aware of the most common presentations:

Pearly nodule: The most classic form. A small, smooth bump with a pearly or waxy sheen and often visible tiny blood vessels (telangiectasias) on the surface.
Flat, coloured patch: A flat, pink or red patch with slightly raised, rolled edges. May resemble an area of chronic eczema or a scab that does not heal.
Scar-like area: A small, white or yellowish area resembling a scar, often with thin, shiny skin over it.
Open sore: A sore that does not heal, bleeds easily or forms a crust, and returns after healing.

BCC most commonly appears on sun-exposed areas: the face (especially the nose), ears, neck, shoulders and upper arms.

Why does basal cell carcinoma occur?

The primary cause of BCC is chronic exposure to ultraviolet (UV) radiation from the sun or tanning beds. UV radiation damages the DNA in skin cells, and when this damage accumulates over time in basal cells, they can begin to grow uncontrollably and form a tumour.

The main risk factors

Chronic sun exposure: Long-term, repeated sun exposure throughout life — especially during childhood and teenage years — is the most important risk factor. Accumulation of UV damage over time is key.
Fair skin tone: People with fair skin, light eyes and blonde or red hair have less melanin pigment and therefore less natural protection against UV radiation.
Age: BCC most commonly affects people over 50 years old, as UV damage accumulates over decades.
Immune suppression: People with organ transplants, HIV/AIDS or those taking immunosuppressant medications have a significantly elevated risk.
Family history: If you have had BCC once, your risk of developing another case is significantly elevated.
Previous injuries: Scars, burns or chronic wounds on the skin can increase the risk in the affected area.

Who gets basal cell carcinoma?

BCC can in principle affect anyone, but certain groups are significantly more vulnerable:

Older adults: Risk increases significantly after age 50, as UV damage has had decades to accumulate.
People with fair skin: Celtic, Scandinavian or other Northern European background is associated with higher risk.
People with high sun exposure: People who work outdoors or spend a lot of time in the sun have an increased risk.
The immunocompromised: Organ transplant recipients and people with HIV have a 10–100 times higher risk than the general population.

Interestingly, BCC is far more common in men than in women — a difference partly attributed to differences in sun exposure patterns and occupational environments.

What can you do about basal cell carcinoma?

The good news is that BCC is highly treatable — especially when detected early. Treatment options depend on the tumour's size, location, depth and your overall health:

🔬 Surgical removal (standard treatment)

Surgical removal (excision) is the most common and effective treatment. The surgeon removes the tumour with a safety margin of healthy skin, and the removed tissue is sent for microscopic examination (histology).

🩺 Mohs surgery (microscopically controlled surgery)

With Mohs surgery the tumour is removed layer by layer, with each layer examined under a microscope while the patient waits. This makes it possible to preserve as much healthy skin as possible — especially important on the face. Recommended for BCC around the eyes, nose, lips or ears.

💡 Radiation therapy (radiotherapy)

Radiation therapy may be used when surgery is not possible — for example in elderly patients or for BCC in locations where surgery would be cosmetically problematic.

💊 Topical treatment

For small, superficial BCCs, topical creams such as fluorouracil (5-FU) or imiquimod may be used. These stimulate the immune system to attack the cancer cells.

Prevention: your best protection

Prevention is paramount. Since BCC is primarily caused by the accumulation of UV damage over decades, the best protection starts early in life:

Sunscreen year-round: Use broad-spectrum sunscreen with SPF 30 or higher every day — even on cloudy days and in winter. Apply 15–30 minutes before sun exposure and reapply every two hours.
Avoid tanning beds: Tanning beds significantly increase the risk of skin cancer. There is no safe form of tanned skin from artificial radiation.
Protective clothing and hats: Wear a wide-brimmed hat, sunglasses and tightly woven clothing. Seek shade during midday hours (12–3 pm), when UV radiation is strongest.
Monthly self-examination: Check your skin from head to toe once a month. Watch for new bumps, spots or sores that do not heal within 4–6 weeks.
Annual dermatologist check-up: Have a professional skin examination at least once a year — and more often if you are in a high-risk group.

Medical classification: Basal cell carcinoma is classified as 2C32 in the WHO's ICD-11. It is characterised by pearly or waxy nodules, often with visible telangiectasias. Treatment is primarily surgical.

Frequently asked questions

Is basal cell carcinoma dangerous?

BCC is the least aggressive form of skin cancer and rarely spreads to other parts of the body. However, it is not harmless — left untreated it can grow deep and damage surrounding tissue, especially on the face. Early treatment gives a cure rate of over 95%.

How does BCC differ from melanoma?

BCC and melanoma are both forms of skin cancer, but they differ markedly. BCC grows slowly, very rarely spreads and has a very high cure rate. Melanoma, on the other hand, can spread quickly to lymph nodes and internal organs and is far more deadly. Melanoma arises from melanocytes (pigment cells) and often appears as a dark mole with irregular borders.

Can BCC return after treatment?

Yes, BCC can recur even after successful treatment. The risk of recurrence depends on whether the entire tumour was removed and on your individual risk profile. People who have had BCC also have an elevated risk of developing new BCCs elsewhere on the skin. Regular follow-up appointments with the dermatologist are therefore important.

When should I contact a dermatologist?

Contact a dermatologist if you notice a new bump, a sore that does not heal within 4–6 weeks, or changes in an existing mole or skin spot. Especially if you are in a high-risk group (fair skin, history of sun exposure, previous skin cancer), regular check-ups are important.

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Disclaimer: This article is for informational purposes only and does not replace professional medical advice. Always consult a dermatologist for personal guidance and assessment of skin changes.