Skin Cancer: What to Know About the Three Main Types

Happy mature woman with senior man in blur background
All Rights Reserved

Skin cancer is the most common form of cancer in the U.S., with one in five Americans likely to be diagnosed at some point during his or her lifetime. Skin cancer can develop when certain skin cells change and start to grow abnormally.

How dangerous a skin cancer is likely to be depends on what type it is, as well as how far it has spread. Here's what to know about the three main types of skin cancer:

Basal cell carcinoma (BCC)

How common: Causes roughly 77 percent of skin cancers, with an estimated 2.8 million diagnosed every year.

How dangerous: Basal cell carcinomas tend to be slow growing and not very dangerous; they only rarely spread to other parts of the body. However, given enough time, a basal cell carcinoma can invade the surrounding tissue and damage cartilage or even bone.

What it looks like: Usually looks like a shiny, slow-growing bump or nodule on the skin. Basal cell carcinomas usually grow in areas exposed to the sun.

Squamous cell carcinoma (SCC)

How common: Causes roughly 20 percent of skin cancers, with an estimated 700,000 diagnosed yearly.

How dangerous: Squamous cell carcinomas are highly treatable but can be dangerous if they grow quickly or if they're allowed to spread. An estimated 1 to 5 percent of squamous cell carcinomas metastasize, causing about 2,500 deaths every year.

What it looks like: Squamous cell carcinomas may look like red or flesh-colored nodules or like red scaly patches of skin. An estimated 60 percent of squamous cell carcinomas develop in preexisting actinic keratoses (a common sun-related precancerous skin lesion). They're commonly found in sun-exposed areas, such as the arms or neck, but they sometimes develop in non-sun-exposed areas, such as in a preexisting scar or burn. They also sometimes develop in the mouth or lip, especially in people who smoke or use tobacco.


How common: Causes only 3 to 4 percent of skin cancers, with an estimated 124,000 diagnosed yearly.

How dangerous: Melanomas are by far the most dangerous type of skin cancer. Although many diagnosed melanomas are superficial and quite treatable, melanomas often become invasive and metastatic. These cause the majority of skin cancer deaths (about 8,800 deaths in 2011).

What it looks like: Melanomas start in melanocytes, which are the pigment cells in the skin, so most melanomas look like abnormal moles, and many develop in a preexisting mole. Some melanomas may look like a large, spreading freckle. Melanomas can develop on sun-exposed skin or may develop on other parts of the body.

If you're worried about possible skin cancer, see 6 Signs to See a Doctor About Possible Skin Cancer and 4 Steps to a Skin Cancer Diagnosis.

Dr. Leslie Kernisan

Leslie Kernisan is a clinical instructor in the University of California, San Francisco, Division of Geriatrics, and maintains a popular blog and podcast at BetterHealthWhileAging. See full bio

8 months, said...

I had two skin cancers at the same time. Both Stage II Squamous Cell Carcinoma Skin cancers. One on my forehead next to hairline. Did MOHS surgery. Other on left lower leg did scrap and burn procedure. Currently changing bandages that won't stay on until they fall off as the doctor told me to let them do. Dr. said the leg cancer area would take months to heal. Forehead almost finished in healing. Scar goes up into my hairline. Now I have Breast Cancer. Learned this during the time I was undergoing treatment on the skin cancers. .

about 3 years, said...

Why didn't the article include pictures?

over 3 years, said...

Squamous cell carcinoma took my 39 year old son's life last year. It presented as a canker on the tongue but entered the bone and lungs eventually killing him 11 months after first being diagnosed. Still haven't gotten over that.

over 3 years, said...

I have had several or more precancer growths removed from my face in the last several years and will have surgery for basel cell below lower lid of right eye in the next week. I urge everyone to have regular exams by a dermatologist.

over 3 years, said...

The words are written even the uneducated can understand them but I see not pictures of what you are talking about so as to READILY identify them. Even though you can eventually get there. Feel like I'm running in circles to get information I thought I was coming here to receive..

over 3 years, said...

I want to know about skin cancer and the first thing I see is a couple smiling!! What is so happy about skin cancer???

over 3 years, said...

hello just wanted you to also know , squamous cell carcinoma cancer also has other risk factors that never seem to get said... besides the suns ultra rays , toxics chemicals, and arsenic and petroleum by-products herbicides pesticides scc cancer..also causes tumors