Diseases & Conditions

Basal cell carcinoma

Basal cell carcinoma is the most common form of nonmelanoma skin cancer. It's also the most easily treated and the least likely to spread.

But though basal cell carcinomas are rarely fatal, they can cause extensive damage to surrounding tissue and bone if they're not removed. Basal cell carcinomas also have a high recurrence rate; if you've had one basal cell carcinoma, you have a good chance of developing another within five years.

Most basal cell carcinomas are caused by long-term exposure to ultraviolet (UV) radiation from sunlight. Avoiding the sun as much as possible is the best protection. Sunscreen is an important part of a sun-safety program, but by itself can't prevent basal cell carcinoma or other forms of skin cancer.

In addition to taking a complete medical history and checking the affected area of skin, your doctor may remove a small skin sample (biopsy) for examination under a microscope. Often, the biopsy is sent to a pathologist who has special expertise in diagnosing skin samples.

A suspected basal cell carcinoma is often biopsied by shaving off the top layers of skin with a surgical blade. Tumors that have spread deeper into the skin may be partially or completely removed (incisional or excisional biopsy). Because all biopsies are likely to leave a small scar, talk to your doctor about the types of biopsies and their potential for scarring before having the procedure.

Basal cell carcinomas that are diagnosed and treated early usually cause no problems. But untreated cancers, especially aggressive morpheaform tumors, can invade and destroy nearby muscles, nerves and bone. One unusual type of basal cell carcinoma — basosquamous — is capable of spreading to other parts of your body.

Basal cell carcinomas are also difficult to eliminate completely. Even after successful treatment, they may recur, often in the same place. Having more than one tumor initially or a tumor on the trunk of your body makes recurrence more likely.

A history of basal cell carcinoma may also increase the chance of developing more serious types of skin cancer, such as squamous cell carcinoma and even malignant melanoma — probably because of long-term sun exposure. Researchers are debating whether having basal cell carcinoma leads to an increased risk of other kinds of cancer.