ADAM Health Encyclopedia

Basal cell carcinoma

Definition

Basal cell carcinoma is a slow-growing form of skin cancer.

See also:

Squamous cell skin cancer

Melanoma

Alternative Names

Causes

Skin cancer is divided into two major groups: non-melanoma and melanoma. Basal cell carcinoma is a type of non-melanoma skin cancer, and is the most common form of cancer in the United States. According to the American Cancer Society, 75% of all skin cancers are basal cell carcinomas.

Basal cell carcinoma starts in the top layer of the skin called the epidermis. It grows slowly and is painless. A new skin growth that bleeds easily or does not heal well may suggest basal cell carcinoma. The majority of these cancers occur on areas of skin that are regularly exposed to sunlight or other ultraviolet radiation. They may also appear on the scalp. Basal cell skin cancer used to be more common in people over age 40, but is now often diagnosed in younger people.

Your risk for basal cell skin cancer is higher if you have:

• Light-colored skin
• Blue or green eyes
• Blond or red hair
• Over-exposure to x-rays or other forms of radiation

Basal cell skin cancer almost never spreads. But, if left untreated, it may grow into surrounding areas and nearby tissues and bone.

Symptoms

Basal cell carcinoma may look only slightly different than normal skin. The cancer may appear as skin bump or growth that is:

• Pearly or waxy
• White or light pink
• Flesh-colored or brown

In some cases the skin may be just slightly raised or even flat.

You may have:

• A skin sore that bleeds easily
• A sore that does not heal
• Oozing or crusting spots in a sore
• Appearance of a scar-like sore without having injured the area
• Irregular blood vessels in or around the spot
• A sore with a depressed (sunken) area in the middle

Exams and Tests

Your doctor will check your skin and look at the size, shape, color, and texture of any suspicious areas.

If skin cancer is a possibility, a piece of skin will be removed from the area so that is can be examined under a microscope. This is called a skin biopsy. This must be done to confirm the diagnosis of basal cell carcinoma or other skin cancers. There are many types of skin biopsies. The exact procedure depends on the location of the suspected skin cancer.

Treatment

Treatment varies depending on the size, depth, and location of the basal cell cancer. It will be removed using one of the following procedures:

• Excision cuts the tumor out and uses stitches to place the skin back together.
• Curettage and electrodesiccation scrapes away the cancer and uses electricity to kill any remaining cancer cells.
• Surgery, including Mohs surgery, which cuts out skin and immediately looks at it under a microscope to check for cancer. The process is repeated until the skin sample is free of cancer.
• Cryosurgery freezes and kills the cancer cells.
• Radiation may be used if the cancer has spread to organs or lymph nodes or for tumors that can't be treated with surgery.

Outlook (Prognosis)

The rate of basal cell skin cancer returning is about 1% with Mohs surgery to up to 10% for other forms of treatment. Smaller basal cell carcinomas are less likely to come back than larger ones.

You should follow-up with your doctor as recommended and regularly examine your skin once a month, using a mirror to check hard-to-see places. Call your doctor if you notice any suspicious skin changes.

Possible Complications

Untreated, basal cell cancer can spread to nearby tissues or structures, causing damage. This is most worrisome around the nose, eyes, and ears.

When to Contact a Medical Professional

Call your health care provider if any you notice any changes in the color, size, texture, or appearance of any area of skin. You should also call if an existing spot becomes painful or swollen, or if it starts to bleed or itch.

Prevention

The best way to prevent skin cancer is to reduce your exposure to sunlight. Ultraviolet light is most intense at midday, so try to avoid sun exposure during these hours. Protect the skin by wearing hats, long-sleeved shirts, long skirts, or pants.

Always use sunscreen:

• Apply high-quality sunscreens with SPF (sun protection factor) ratings of at least 15.
• Look for sunscreens that block both UVA and UVB light.
• Apply sunscreen at least 30 minutes before going outside, and reapply it frequently.
• Use sunscreen in winter, too.

Examine the skin regularly for development of suspicious growths or changes in:

• Color
• Size
• Texture
• Appearance

Also note if an existing skin sore bleeds, itches, is red and swollen (inflamed), or is painful.

Habif TP. Clinical Dermatology. 4th ed. St. Louis, Mo: Mosby, Inc. 2004:724-735.

Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKena WG. Clinical Oncology. 3rd ed. Orlando, Fl: Churchill Livingstone; 2004:449-452.

Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001:772-773.