Basal Cell Carcinoma

July 5, 2023
This page was reviewed under our medical and editorial policy by David Winchester, M.D., FACS, clinical professor, Department of Surgery, City of Hope^® Cancer Center Chicago

Basal cell skin cancer is the most common form of skin cancer. Approximately 80% of all skin cancers are basal cell carcinomas (BCC), meaning they occur in the skin’s basal cell layer, according to the American Cancer Society.

The other two main types of skin cancer are squamous cell cancer and melanoma. All types of skin cancer are serious and should be properly diagnosed and treated by a doctor.

The skin’s uppermost layer is called the epidermis, and the bottom layer of the epidermis is the basal cell layer. If skin cancer starts in the basal cell layer, it’s a basal cell carcinoma.

Basal cell skin cancers tend to grow slowly and rarely spread, but this doesn’t mean you should ignore them. Untreated basal cell cancer can invade other tissues under the skin. It can also recur. If you’ve had basal cell skin cancer in the past, it may come back in the same place or elsewhere on the body.

What Do The Types of Basal Cell Carcinoma Look Like?

There are four types of basal cell carcinomas, listed below, each of which looks slightly different from the others. 

Nodular basal skin cell cancers: This type looks like a pimple, raised from the skin, and may appear flesh-colored, pink, pearly or shiny. It also may have little red blood vessels inside and a slightly raised edge. It’s slow-growing and may turn into an open sore and bleed. 

Superficial spreading basal cell carcinoma: This type appears like a pink or red scaly patch. It’s flat to the skin and may develop a crust. The outer edge may look pearl-colored with small white bumps. 

Sclerosing or infiltrating basal cell cancers: Also called morpheaform BCCs, these lighter-colored patches on the skin are shiny and smooth and may look like a scar. They may be difficult to see with undefined borders. They may also have indentations, little red blood vessels and open sores or crusts. 

Pigmented basal cell skin cancers: These may have a color to them, appearing brown, blue, black or red. 

Basal cell and squamous cell carcinomas are the two most common types of skin cancer. According to the American Cancer Society, about 80% of nonmelanoma skin cancers are basal cell carcinomas, while about 20% are squamous cell carcinomas. 

Both form in the outer layer of the skin, but in different types of cells: 

• Squamous cell carcinoma starts in the skin’s squamous cells — the flat cells that shed off of the skin constantly. 
• Basal cell carcinoma begins in the basal cells, the base of the skin’s outermost layer. These cells are always growing, making new cells that push old ones off the skin. 

Both skin cancers are most commonly the result of cell changes caused by ultraviolet (UV) light and appear on sun-exposed areas of the body. However, squamous cell cancers may also grow in scars or skin sores that don’t heal on other parts of the body. Sometimes, they grow in areas of the body that are hard to examine, such as between the toes or around the genitals. 

Basal cell carcinomas rarely spread to other parts of the body. It’s much more common for squamous cell carcinomas to spread.

Exposure to the sun’s ultraviolet rays is the top risk factor for all types of skin cancer, including basal cell carcinoma. Basal cell skin cancers occur on parts of the body that are exposed to sun, including the neck, scalp, chest, shoulders and back. If you had sunburns as a child, you’re at greater risk for basal cell skin cancers. 

This form of skin cancer is more common in people older than 50, but it can develop in younger people with a history of extensive sun exposure, too. 

In addition to a history of exposure to the sun or other UV radiation, the risk for developing basal cell skin cancer increases if you have: 

• Light or freckled skin 
• Blue, green or gray-colored eyes 
• Red or blonde hair 
• Multiple moles 
• A family history of skin cancer 
• A challenged immune system from medicines, including those meant to suppress the immune system after an organ transplant 
• Other skin diseases such as nevoid basal cell carcinoma syndrome, a hereditary condition characterized by multiple basal cell skin cancers 
• A history of photodynamic therapy, which uses special drugs along with a light source to kill cancer cells 
• A history of smoking

The best way to reduce the risk for basal cell or any type of skin cancer is to: 

• Apply broad-spectrum sunscreen with an SPF of 30 or higher, making sure to cover all exposed areas and reapply it frequently. 
• Avoid the sun when it’s strongest. 
• Wear wide-brimmed hats and long sleeves or long pants when out under the sun's rays. 
• Wear sunglasses that block UV light, which can prevent damage to the thin skin around your eyes. 
• Avoid indoor tanning. 
• Schedule yearly skin cancer checks with a dermatologist. 
• Conduct monthly self-checks for skin changes.

Skin cancer protection tips

When diagnosing basal cell carcinoma, the doctor may look for symptoms that may include: 

• An open sore that won’t heal, but may bleed, ooze or crust 
• A shiny or pearly pink, red, or flesh-colored bump 
• A raised, rolled edge and a crusted indentation in the center 
• A white, waxy or yellow scar-like area 

Knowing what to look for can help you stay one step ahead of basal cell skin cancers.

If you’re concerned about a mark on your skin, schedule a visit with your dermatologist. It’s better to be safe than sorry. Your doctor will examine the spot and if he or she is concerned, a biopsy is the next step. This involves taking a sample of the lesion and sending it off to a lab for analysis. The process can take around a week or more to get results.

Treatment plans for basal cell carcinoma is based on its size, depth and location. Your surgeon may opt to excise the cancer, or cut it out and stitch the remaining skin back together. 

Mohs surgery is a skin cancer treatment that removes a mole layer by layer. The surgeon looks at each layer under a microscope and continues to remove more layers until there’s no evidence of the cancer. This tends to be preferred if the basal skin cell carcinoma is on the nose, ears and other areas of the face. 

Reconstructive surgery is a type of treatment that’s sometimes needed to repair the areas where skin cancer has been removed. 

Treatments other than surgery may also be options, including: 

• Cryosurgery to freeze and kill the cancer cells 
• Medicated skin creams 
• Photodynamic therapy 
• Radiation therapy, which uses X-rays to kill cancer cells (an option when basal cell cancer can’t be removed surgically) 

If basal cell cancer has spread to other parts of your body, options may include newer chemotherapies. Both Erivedge® (vismodegib) and Odomzo® (sonidegib) block a key signaling pathway that encourages basal cell skin cancers to grow and spread.