Basal cell carcinoma is a type of skin cancer. Basal cell carcinoma begins in the basal cells â a type of cell within the skin that produces new skin cells as old ones die off.
Basal cell carcinoma often appears as a slightly transparent bump on the skin, though it can take other forms. Basal cell carcinoma occurs most often on areas of the skin that are exposed to the sun, such as your head and neck.
Most basal cell carcinomas are thought to be caused by long-term exposure to ultraviolet (UV) radiation from sunlight. Avoiding the sun and using sunscreen may help protect against basal cell carcinoma.
Basal cell carcinoma usually develops on sun-exposed parts of your body, especially your head and neck. This skin cancer appears less often on the trunk and legs, and basal cell carcinoma can â but rarely â occur on parts of your body usually protected from the sun such as genitals or women's breasts.
Basal cell carcinoma appears as a change in the skin, such as a growth or a sore that won't heal. These changes in the skin, or lesions, usually have one of the following characteristics:
Make an appointment with your doctor if you observe changes in the appearance of your skin, such as a new growth, a change in a previous growth or a recurring sore.
Basal cell carcinoma occurs when one of the skin's basal cells develops a mutation in its DNA.
Basal cells are found at the bottom of the epidermis â the outermost layer of skin. Basal cells produce new skin cells. As new skin cells are produced, they push older cells toward the skin's surface, where the old cells die and are sloughed off.
The process of creating new skin cells is controlled by a basal cell's DNA. A mutation in the DNA causes a basal cell to multiply rapidly and continue growing when it would normally die. Eventually the accumulating abnormal cells may form a cancerous tumor â the lesion that appears on the skin.
Much of the damage to DNA in basal cells is thought to result from ultraviolet (UV) radiation found in sunlight and in commercial tanning lamps and tanning beds. But sun exposure doesn't explain skin cancers that develop on skin not ordinarily exposed to sunlight. Other factors can contribute to the risk and development of basal cell carcinoma, and the exact cause may in some cases not be clear.
In order to assess any growths or changes in your skin, your doctor or a specialist in skin conditions (dermatologist) will conduct a medical history and exam.
Your doctor will conduct a general physical exam and ask you questions about your medical history, changes in your skin, or any other signs or symptoms you've experienced.
Questions may include:
Your doctor will examine not only the suspicious area on your skin but also the rest of your body for other lesions.
Your doctor may do a skin biopsy, which involves removing a small sample of a lesion for testing in a laboratory. This will reveal whether you have skin cancer and, if so, what type of skin cancer. The type of skin biopsy you undergo will depend on the type and size of the lesion.
Complications of basal cell carcinoma can include:
You may reduce your risk of basal cell carcinoma if you:
Factors that increase your risk of basal cell carcinoma include: