Basal Cell Carcinoma

Basal cell carcinoma develops from the basal cells, which are located in the deepest layer of the epidermis (the outer layer of the skin). These cells are responsible for continually producing new skin cells throughout your life.

Years of ultraviolet (UV) exposure from the sun or tanning beds can damage the DNA inside these cells. Over time, that damage can cause the cells to grow uncontrollably, leading to basal cell carcinoma.

Basal cell carcinoma is by far the most common skin cancer in the United States, with millions of new cases diagnosed each year.

The good news is that basal cell carcinoma almost never spreads (metastasizes) to distant organs. However, that does not mean it should be ignored. If left untreated, basal cell carcinoma continues to enlarge. It can invade deeper tissues, destroying healthy skin, muscle, cartilage, and bone. Larger tumors often require more extensive surgery and may leave larger scars than lesions treated early. Simply put, basal cell carcinoma is easiest to treat when it is found early.

The primary cause is cumulative ultraviolet (UV) radiation exposure. Common risk factors include:

• Fair skin
• Blue or green eyes
• Blonde or red hair
• A history of frequent sunburns
• Years of outdoor work or recreation
• Indoor tanning bed use
• Increasing age
• A weakened immune system
• Previous radiation therapy
• A personal history of skin cancer

While basal cell carcinoma most commonly affects older adults, it can also occur in younger adults, particularly those with significant UV exposure or a history of indoor tanning.

Basal cell carcinoma usually develops on areas that receive the most sun exposure. Common locations include:

• Face
• Nose
• Eyelids
• Ears
• Scalp
• Neck
• Chest
• Shoulders
• Back
• Arms

The face is a particularly common location because of its significant cumulative sun exposure.

Basal cell carcinoma does not always look the same. In fact, it can have several different appearances:

1. A Pearly Bump: Many basal cell carcinomas appear as a shiny, flesh-colored or pink bump. They may have tiny visible blood vessels, called telangiectasias, running across the surface.
2. A Sore That Doesn’t Heal: A spot that repeatedly scabs, bleeds, seems to heal, and then comes back should always be evaluated. Patients sometimes mistake these lesions for pimples, scratches, or shaving injuries that simply refuse to go away.
3. A Pink Patch: Some basal cell carcinomas appear as flat, slightly scaly pink patches that resemble eczema or irritated skin.
4. A Scar-Like Area: Certain basal cell carcinomas grow as firm, pale, scar-like areas. These tumors can sometimes extend farther beneath the skin than their surface appearance suggests.
5. A Pigmented Spot: Basal cell carcinoma can occasionally contain brown, blue, or black pigment and may resemble a mole or other pigmented growth. Because basal cell carcinoma can have many appearances, any persistent, bleeding, or changing spot deserves evaluation by a dermatologist.

Diagnosis usually begins with a skin examination. Your dermatologist may examine the lesion using a dermatoscope, a specialized magnifying device that provides a more detailed view of structures within the skin.

If a lesion appears suspicious, a small skin biopsy is usually performed. A biopsy typically takes only a few minutes using local anesthetic. The tissue is then examined under a microscope to determine whether skin cancer is present and, if so, what type.

Treatment depends on several factors, including:

• Size
• Location
• Depth
• Histologic subtype
• Whether it has been treated previously
• Overall patient health

Fortunately, cure rates for appropriately treated basal cell carcinomas are extremely high.

Most patients do very well after basal cell carcinoma treatment. However, having one basal cell carcinoma is an important marker of previous UV damage and increases the likelihood of developing additional skin cancers in the future. For this reason, treatment of the original cancer is only one part of long-term care. Ongoing sun protection, self-examination, and routine skin examinations with a dermatologist are also important.

Yes, although there are two different things patients may mean when they ask whether basal cell carcinoma can “come back.”

The first is a true recurrence. This occurs when some cancer cells remain after treatment and the basal cell carcinoma eventually grows again in the same location. Recurrence is uncommon after appropriate treatment, but the risk varies depending on the tumor’s size, location, microscopic growth pattern, previous treatment, and the treatment method used.

The second, and often more common, situation is the development of an entirely new basal cell carcinoma somewhere else on the skin.

A person who has already developed one basal cell carcinoma has demonstrated that their skin has accumulated enough UV damage to produce a skin cancer. That same sun damage may affect many other areas of the skin, which is why another basal cell carcinoma, squamous cell carcinoma, or other skin cancer may develop in the future.

This does not mean that the original basal cell carcinoma has spread. Instead, it represents a separate skin cancer arising independently.

If a previously treated area begins to bleed, develop a new bump, form a persistent scab, or otherwise change, it is important to have it evaluated. Regular full-body skin examinations are also helpful for detecting completely new skin cancers before they become larger or more difficult to treat.

For many patients who have had a basal cell carcinoma, full-body skin examinations every six to twelve months may be recommended.

The appropriate schedule depends on factors such as:

• Number of previous skin cancers
• Degree of sun damage
• Age
• Immune status
• Family and personal history
• Other individual risk factors

Patients who develop multiple skin cancers or who are otherwise at particularly high risk may need more frequent examinations. Regular surveillance allows new or recurrent skin cancers to be detected while they are still small and highly treatable.

While not every basal cell carcinoma can be prevented, reducing UV exposure can lower your risk of future skin cancers.

We recommend:

• Wearing a broad-spectrum SPF 30 or higher sunscreen
• Reapplying sunscreen approximately every two hours when outdoors and after swimming or sweating
• Wearing wide-brimmed hats and sun-protective clothing
• Seeking shade when possible
• Avoiding tanning beds
• Performing regular self-skin examinations
• Scheduling routine skin examinations with your dermatologist

Sun protection remains important even after years of previous sun exposure. Protecting your skin today can help reduce additional UV damage in the years ahead.

You should schedule an evaluation if you notice:

• A sore that won’t heal
• A spot that repeatedly bleeds or scabs
• A shiny or pearly bump
• A persistent pink or scaly patch
• A new or changing growth
• A change within the scar or skin where a previous cancer was treated

Many suspicious-looking lesions are ultimately benign. However, when a lesion is skin cancer, identifying it early often makes treatment easier.