skin disorders
Basal Cell Carcinoma
Introduction
Basal cell carcinoma, the most common skin cancer, originates in certain 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. This cancer can often be identified by sight, but doctors usually do a biopsy. The cancer is usually removed, but sometimes people may be given chemotherapy drugs applied to the skin, immunotherapy, or, occasionally, radiation therapy or medications taken by mouth. 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 Overview of Skin Cancer . Approximately 2 million people develop this type of cancer in the United States each year. Basal cell carcinoma is most common among people who have light skin and a history of sun exposure. It is very rare among people with dark skin. Basal cell carcinoma usually develops on skin surfaces that are exposed to sunlight, commonly on the head or neck, and may develop in a type of birthmark that often appears on the scalp (nevus sebaceus). Basal cell carcinoma also may develop in people who have certain hereditary disorders, such as xeroderma pigmentosum, Gorlin syndrome, and Bazex syndrome. 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. 