Basal cell carcinoma

Also known as rodent ulcers

Basal cell carcinomas are the most common and the least serious form of skin cancer – as long as they are treated.

Key points

  1. Basal cell carcinomas are a type of non-melanoma skin cancer.
  2. They often appear as a pale, red or pearly smooth lump, usually on your face or neck.
  3. Although more common among older people, they can develop in people in their early 40s or even younger.
  4. Most basal cell carcinomas are caused by long-term exposure to ultraviolet (UV) radiation from sunlight.
  5. Almost all basal cell carcinomas occur on parts of your body that receive the most exposure to the sun.
  6. They tend to be slow growing and rarely spread to other parts of your body.

What is basal cell carcinoma?

Basal cell carcinomas (BCC) occur when a mutation develops in one of your skin's basal cells. Basal cells are found at the bottom of the epidermis –the outermost layer of your skin. Basal cells produce new skin cells as old ones near the surface die off.

Sun exposure is the main cause of damage leading to basal cell carcinoma. As a result, almost all basal cell carcinomas occur on parts of your body that receive the most exposure to the sun.

What causes basal cell carcinomas?

The main cause of damage leading to basal cell damage is a combination of:

  • long-term, everyday sun exposure, and
  • occasional intense exposure, usually leading to sunburn. 

In some cases, these are the result of damage caused by things such as burns, scars, infections, vaccinations or tattoos.

Who is most at risk of developing a basal cell carcinoma?

You are at highest risk of developing a basal cell carcinoma if you:

  • have pale skin and burn easily
  • have spent a lot of time outdoors for work or leisure
  • live in a sunny climate
  • use sunbeds or sunbathe
  • have previously had a basal cell carcinoma.

Where do basal cell carcinomas appear?

Almost all BCCs occur on parts of your body that receive the most exposure to the sun, such as your face, ears, neck, scalp, shoulders and back. They occur less often on other parts of your body or legs. In rare cases, they can appear on parts of your body that are normally protected from the sun.

What do basal cell carcinomas look like?

Basal cell carcinomas often appear as a change in your skin, such as a growth or a sore that does not heal. 

The main features are:

  • slow growing – months to years
  • a pearly white, skin-coloured or pink bump that is translucent (you can see a bit through the surface)
  • waxy, small, raised lesions with an indented centre
  • brown or blue-black areas, in some cases
  • a tendency to bleed or turn into an ulcer
  • scaly, oozing or crusted areas
  • varying in size from a few millimetres to several centimetres in diameter.

What should I do if I think I have a basal cell carcinoma? 

If you notice a change to or growth on your skin, make an appointment to see your doctor straight away. Your doctor will assess the size, location and look of the growth. They will also ask you how long you have had it, whether it bleeds or itches, etc.

If your doctor thinks the growth may be cancer, they may take a small sample of tissue (a biopsy). The tissue sample will be sent to a laboratory and examined under a microscope. Your doctor will let you know whether the cells were cancerous or not, and will recommend appropriate treatment if necessary.

How are basal cell carcinomas treated?

Treatment of basal cell carcinoma depends on its type, size and location and other factors, such as your preference.

Options include:

  • surgical removal of the cancer
  • freezing it with liquid nitrogen
  • topical therapies (eg, creams)
  • photodynamic therapy
  • radiation treatment. 

If you have a basal cell carcinoma, talk with your doctor about which treatment option is best for you. Treatment has a high success rate, provided the skin cancer is found at an early stage. Your doctor may want to schedule a future appointment to check for new lesions.

Read more about skin cancer treatment

How can I prevent basal cell carcinoma from recurring?

Most basal cell carcinomas can be treated and cured. However, it is possible for these types of cancers to recur or for new skin cancers to appear.

Do the following to reduce the risk of new cancers occurring:

  • Keep all follow-up appointments with your GP or skin specialist.
  • Regularly check all your skin (from head to toe). If you see anything that is growing, bleeding or in any way changing, go and see your doctor straight away. See skin checks
  • Protect your skin from the sun and avoid indoor tanning. This is essential to prevent further damage, which can increase the risk of getting another skin cancer.

Ways to protect your skin

  • Avoid outdoor activities when the sun is strongest – between 10 am and 4 pm from September to April in New Zealand.
  • Wear sunscreen and lip balm daily that offer SPF 30 or higher sun protection.
  • Use sunscreen that offers broad-spectrum (UVA/UVB) protection and is water resistant. 
  • Apply the sunscreen and lip balm to dry skin 15 minutes before going outdoors. 
  • Apply the sunscreen to every part of your body that will not be covered by clothing. Reapply it every two hours if you are swimming or sweating.
  • Whenever possible, wear a wide-brimmed hat, long sleeves and long pants. 
  • Wear sunglasses to protect the skin around your eyes. 
  • Avoid getting a tan and never use a tanning bed or sun lamp. 

See also sun safety

Learn more

Basal cell carcinoma staging, treatment information and image library DermNet NZ
Basal cell carcinoma patient information sheet British Association of Dermatologists


  1. Guidelines for the management of basal cell carcinoma Telfer NR, Colver GB, Morton CA. Br J Dermatol 2008; 159: 35-48.
  2. Basal cell carcinoma - tips for managing American Academy of Dermatology
  3. Basal cell carcinoma e-medicine dermatology, the online medical reference textbook.
Credits: Health Navigator Editorial Team.