Basal cell carcinoma
What is basal cell carcinoma?
Around three quarters of skin cancer cases are diagnosed as basal cell carcinoma skin cancer.
This skin cancer forms in basal cells deep in the skin around hair follicles, usually on parts of the body most exposed to the sun. These include the face, neck, or upper back.
Basal cell cancers do not usually spread or metastasise to other parts of the body.
What are risk factors for developing basal cell carcinoma?
Light-coloured skin and sun exposure are both important factors in the development of basal cell carcinomas. About 20% of these skin cancers, however, occur in areas that are not regularly sun-exposed. The face, however, remains the most common location for basal cell lesions. Weakening of the immune system, whether by disease or medication, can also increase the risk of developing basal cell carcinoma.
Ultraviolet (UV) radiation from the sun is the main cause of skin cancer. Artificial sources of UV radiation, such as sunbeds and tanning booths, can also cause skin cancer. The risk of developing skin cancer is also affected by where a person lives. People who live in areas with high levels of UV radiation from the sun are more likely to develop skin cancer. Worldwide, the highest rates of skin cancer are found in South Africa and Australia, which are areas with high levels of UV radiation. In addition, skin cancer is related to lifetime exposure to UV radiation. Most skin cancers appear after age 50, but the sun's damaging effects begin at an early age. Therefore, protection should start in childhood in order to prevent skin cancer later in life.
What does basal cell carcinoma look like?
A basal cell carcinoma usually begins as a small, dome-shaped bump and is often covered by small, superficial blood vessels called telangiectases. The texture of such a spot is often shiny and translucent, sometimes referred to as "pearly." It is often hard to tell a basal cell carcinoma from a benign growth like a flesh-coloured mole without performing a biopsy. Some basal cell carcinomas contain melanin pigment, making them look dark rather than shiny.
Basal cell carcinomas grow slowly, taking months or even years to become sizeable. Although spread to other parts of the body (metastasis) is very rare, a basal cell carcinoma can damage and disfigure the eye, ear, or nose if it grows nearby.
How is basal cell carcinoma diagnosed?
To make a correct diagnosis, doctors usually remove all or part of the growth by performing a biopsy. This usually involves injecting a local anaesthetic and taking a sample by scraping off a small piece of skin. This method is referred to as a shave biopsy. The skin that is removed is then examined under a microscope to check for cancer cells.