Basal cell carcinoma, also called epithelioma, is the uncontrolled growth of the skin's basal cells. These are the cells that line the deepest layer of the epidermis, the skin's outermost layer. This type of cancer rarely spreads to other parts of the body.
It is mainly caused by repeated long-term exposure to sunlight. Light-skinned people who spent a lot of time in the sun as children, or who spend time in tanning booths, are especially susceptible. X-ray treatments for acne and exposure to industrial pollutants such as arsenic and hydrocarbons also increase the risk of developing basal cell carcinoma.
Basal cell carcinoma is the most common skin cancer in the United States, with nearly 3 million cases diagnosed each year.
Symptoms of basal cell carcinoma
Basal cell carcinoma usually begins as a painless bump or nodule that grows slowly. Later, it becomes an open ulcer with a hard edge. Nearly 90% of basal cell carcinomas occur on the face, but they can appear on any part of the body that is sometimes exposed to the sun—the face, ears, neck, back, chest, arms, and legs.
Although basal cell carcinoma almost never spreads to other organs and is rarely fatal, it can invade surrounding tissue and be disfiguring if not treated.
Preventing basal cell carcinoma
Basal cell carcinoma is curable, but prevention — not getting too much sun — is the best medicine. Use sunscreen or sun-filtering clothing, and wear a hat.
Diagnosing basal cell carcinoma
Your doctor can diagnose basal cell carcinoma by examining your skin and performing a biopsy.
Treating basal cell carcinoma
Basal cell carcinomas must be removed. Methods include
- surgery (cutting)
- cryosurgery (freezing)
- radiation therapy
- electrosurgery (which uses electrical current to kill cells)
- and curettage (scraping)
A painstaking procedure called Mohs surgery minimizes the amount of tissue removed. It is often performed when the cancer is located in the skin folds around the nose, at the corners of the eyes, and around the ears.
If you have had one basal cell carcinoma, you are at higher risk of developing others. Regular checkups are recommended for five years after removal of a basal cell carcinoma to make sure the cancer has not returned, and no new ones have appeared.
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.