Written or medically reviewed by a board-certified physician. See About.com's Medical Review Policy.

Updated August 05, 2015.

Basal cell carcinoma (BCC) is the most common type of skin cancer, with approximately 2.5 million cases annually in the United States. Due to its prevalence, it is important to be aware of the signs of BCC so that early treatment can be sought. Basal cell carcinoma can be easily treated during the early stages of their growth, but if they continue to grow without treatment, they can cause serious disfigurement and their removal may become more complicated.

While rare, there are certain aggressive forms of BCCs that can be fatal if left untreated.

What is basal cell carcinoma?

Basal cell carcinoma is a tumor of the epidermis, the outermost layer of the skin. It is caused by chronic exposure to ultraviolet radiation and is most common in patients with a history of prolonged sun exposure, sunburns and tanning bed use. This is a slow growing tumor that doubles in size about once per year. These lesions are most common on sun-exposed surfaces.

BCCs may manifest as shiny red, pink or brown patches, open sores, shiny bumps, or flesh-colored growths with blood vessels in them. Because BCCs vary dramatically in their appearance, many people are unaware that they have skin cancer until they receive a diagnosis from their dermatologist. As such, it’s important to have a dermatologist promptly examine any abnormal growths on your skin so that treatment can begin promptly. Skin self-checks are also important, as they can help you identify any new or unusual growths.

It is estimated that 3 out of 10 Caucasians will develop a BCC at some point in their life. Fortunately, BCCs rarely metastasize and cause cancer in other parts of the body. Treatment for a BCC, however, should not be delayed as the tumor can become difficult to remove as it grows or can lead to serious disfigurement, especially on if it occurs on the face.

Causes and risk factors

Researchers believe that the majority of BCCs occur when a basal cell’s DNA becomes damaged by the sun’s ultraviolet rays. Long-term exposure combined with occasional, concentrated exposure (like the kind that causes sunburn) is thought to contribute to cell damage that causes BCC. As a result, BCCs are often found on parts of the body that receive the most exposure to sunlight, such as the face, scalp, shoulders and neck. There is no known pre-cancerous lesion of basal cell carcinoma, therefore it’s important to get checked regularly to find these lesions at their smallest possible size.

A particularly dangerous place where basal cell carcnima can develop is the eyelid or the skin right next to the eye. If left untreated, these lesions can invade into the eye itself or the skin around it. This can cause a lot of morbidity (defects) with surgery. In the worst cases, removal of the eye itself may be necessary.

While anyone who is regularly exposed to the sun can get BCC, certain individuals are at a higher risk of developing this type of skin cancer. Risk factors include:

• Having fair skin, blond or red hair, and light colored eyes
• A family history of BCC or other types of skin cancer
• Age – BCCs are more commonly found on older people, but the average age of patients with BCCs is steadily decreasing
• Gender – historically, men are more likely to develop BCCs than women, but this trend is becoming less pronounced as more and more women develop BCCs
• Having an occupation or hobby that requires long periods of time spent in the sun

Recurrence

Individuals who have had one BCC are more likely to develop another one in the coming years. The new growth can form in the same location or somewhere entirely new. For this reason, anyone who has had a BCC should undergo routine skin exams with a qualified dermatologist. Patients who have had a BCC on the scalp or nose are particularly susceptible to recurrences within two years of the original growth being removed.

Symptoms of basal cell carcinoma

As discussed above, the appearance of BCCs varies greatly. Below is a list of symptoms and descriptions of BCCs.

• A shiny, hard bump that may be mistaken for a pimple or mole
• Pearly skin nodule
• A dome-shaped skin growth with blood vessels in it
• Pink or red patches with a scaly, dry appearance similar to eczema
• Red or pink open sores
• Patch of thickened skin or scar tissue
• Dark brown or black colored growths
• Fragile growths that bleed easily

To learn more about the appearance of BCCs, you can view these images of BCCs on real patients. Remember that you cannot rely on self-diagnosis to identify BCCs. It is important to have any new or unusual growth examined by a dermatologist promptly.

Diagnosis

To diagnose basal cell carcinoma, a skin doctor may examine the patient’s skin and perform a skin biopsy. During the skin examination, the doctor will carefully examine the lesion and also check over the rest of the patient’s to body to identify any additional growths that may be of concern. If the doctor determines that the growth is not normal, he or she will then perform a biopsy. This involves excising a small portion of the growth so that it can be tested in a laboratory. If skin cancer is suspected, the doctor will then discuss the most appropriate treatment options.

Treatments

When skin cancer is diagnosed, patients may feel understandably upset and nervous. The good news is that BCCs responsible very well to treatment, especially when they are identified and treated early. There are a number of treatments available to remove or destroy basal cell carcinomas. The most popular treatments include:

• Surgical excision is one of the more common methods for removal of BCCs. This treatment is typically performed under local anesthesia and involves the removal of both the tumor and a margin of skin around the tumor. After the tumor and skin have been removed, they will be sent to a laboratory for testing to ensure that all of the cancerous areas have been removed.
• Mohs surgery is a specialized skin surgery that is performed by a dermatologist who has been trained in this method. During the procedure, the tumor is removed layer by layer, with each layer being examined under a microscope throughout the procedure. The doctor will continue to remove layers until he or she is certain that no cancerous cells remain. Mohs surgery is preferred for basal cells on the face or for those lesions that have recurred or have an aggressive growth pattern.
• Electrodessication and curettage (ED&C) is one of the most common ways to treat BCC. During the procedure, the surface of the lesion is scraped away with a curette and then an electric needle is used to burn the base and prevent further growth. This procedure often has the lest amount of down time for the patient and no stiches are required.
• Topical medications may be prescribed to treat superficial BCCs. The most commonly used drugs are imiquimod and fluorouracil, which are applied for several weeks until the lesion has disappeared.
• Oral treatment can be used, especially for advanced or metastatic lesions. Two agents are currently available and approved by the FDA. While these do have some side effets, these medications are generally well tolerated and have good efficacy results.