Basal cell carcinoma is a cancer that originates in the cells of the outer layer of the skin (epidermis).
Usually, a small, shiny bump appears on the skin and enlarges slowly.
The bumps may break open and form a scab, sometimes with bleeding, or become flat, resembling a scar.
Although this cancer can often be identified by sight, doctors usually do a biopsy.
The cancer is usually removed, but sometimes people may be given chemotherapy drugs applied to the skin or, occasionally, radiation therapy or drug therapy.
Basal cells are in the lowest layer of the epidermis (the outer layer of the skin). Although basal cell carcinoma may not develop from the basal cells, the disease is so named because the cancer cells look like basal cells under a microscope.
Basal cell carcinoma is the most common type of skin cancer. More than 2.8 million people develop this type of cancer in the United States each year. It is more common among fair-skinned people with a history of sun exposure and is very rare among dark-skinned people. Basal cell carcinoma usually develops on skin surfaces that are exposed to sunlight, commonly on the head or neck.
The tumors enlarge very slowly, sometimes so slowly that they go unnoticed as new growths. However, the growth rate varies greatly from tumor to tumor, with some growing as much as ½ inch (about 1 centimeter) in a year.
Basal cell carcinomas rarely spread (metastasize) to other parts of the body. Instead, they invade and slowly destroy surrounding tissues. When basal cell carcinomas grow near the eyes, ears, mouth, bone, or brain, the consequences of spread can be serious and can lead to death. Yet, for most people, the tumors simply grow slowly into the skin.