What is the Difference in Precancerous Skin Growths and Skin Cancer?

6 min read

What is the Difference in Precancerous Skin Growths and Skin Cancer?

Have you ever wondered what causes a common mole to develop into skin cancer? Most moles never cause problems and don't progress to skin cancer. 

There are a number of reasons you may want to have a doctor or dermatologist look at a skin growth:

Because you have a new spot or there has been a change doesn’t automatically mean it’s cancerous. Let’s talk about what you should be looking for and what to do if you notice something different on your skin.

What is Precancerous Skin Growth?

Precancerous skin growths develop on skin that has a lot of sun exposure over time without proper protection. While it’s not considered cancer yet, it can turn into it in the future. While many forms of precancerous skin growths can form after the age of 40, it can also happen at an earlier age, especially if you live, or have lived, in areas with a lot of sunshine.

Actinic keratosis (AK) is the most common type of growth that can become precancerous. Some people say an AK feels rough, like a spot of sandpaper on the skin. Many oncologists consider AKs as early squamous cell cancers (SCC). If left untreated, AKs will likely progress into nonmelanoma skin cancer, mainly SCCs.

If precancerous skin growths are left untreated, they may result in one of the following types of skin cancer:

  • Basal cell carcinoma is the most common form of skin cancer, according to the American Cancer Society, making up the majority of skin cancer cases in the United States. If found early, it is easily treatable.

  • Squamous cell carcinoma is less common but more serious because it is more likely to spread to other parts of the body. It can be treated successfully if detected early. The cure rate is more than 90%. However, if it spreads (which happens in 1 to 5% of cases), it is much harder to treat.

  • Melanoma is severe skin cancer and is harder to treat. In as few as six weeks, it can spread quickly to other parts of the body or internal organs.

Common Skin Growths to Look For

The most common growths on the skin include moles, freckles, skin tags, and warts.


Moles are brown or black skin growths that can appear anywhere on the skin. Most show up early childhood, and most people have 1- to 40 moles by age 25. Moles usually change very slowly but can become raised or change color. Some never change or even disappear.

Moles present at birth (in about 1% of infants) are slightly more likely to develop into melanoma. Moles larger than a pencil eraser, with an irregular shape or uneven color, are also more likely to become cancerous. Moles that appear after age 25 and look different than your other moles are also more likely to become cancerous. 

Skin Tags

Skin tags are a general term for any small flap of tissue that hangs off your skin. Usually harmless, they appear on the neck, chest, armpits, groin area, or under the breasts. They are more common in women who are overweight and in older people. You may become aware of a skin tag when it becomes irritated by clothing or other skin rubbing against it. Skin tags are not cancerous. However, sometimes people mistake a cancerous growth for a skin tag.

Age Spots

Brown spots or age spots are usually harmless skin discolorations (usually brown) and are called lentigo. Lentigines are more common among people with fair skin. Usually caused by sun exposure, some spots are hereditary or caused by radiation therapy. They are often clumped together in an area, have smooth borders and are painless.


Freckles are very common, with small brown spots on the face, neck, chest, and arms. Light-skinned people or those with light or red hair often have more freckles in the summer because of more sun exposure. Freckles are not a health threat.


Warts (Seborrheic keratoses) are usually brown, tan or black, and are found on the chest, back and head. They are more common with age but rarely lead to skin cancer.

What to Watch For 

Although skin cancer can appear anywhere on your body, most develop on parts of the body that get the most sun -- face, head, neck, hands, and arms. 

You might notice a precancerous spot that has changed or is newly developed. Let’s talk about what you might see. 

Basal cell cancers may have these characteristics, according to the American Cancer Society:

  • Looks like a scar with a flat, firm, yellowish area
  • Reddish patch that may be raised or itchy
  • Shiny, pearl-colored bump that may be tinged with pink, red, blown, or even blue 
  • Pink growth with raised edges but a lower center; may have blood vessels that spread out like the spokes of a bicycle wheel.
  • An open sore that doesn't heal, or it heals and then comes back, it may bleed, ooze or develop a crusty surface

Squamous cell cancers may look like this:

  • Rough or scaly red patches, which can bleed or form a scaly crust 
  • Raised growths or lumps
  • Open sores that don't heal or sometimes heal and come back
  • Wart-like growths

Melanoma can look like:

  • A new spot or a spot that is changing is size, shape, or color
  • A spot that looks different from other moles, freckles, or warts on your body

Some skin cancers don't include any of these symptoms. Talk to your doctor about any changes or new spots on your skin. These can include:

  • A sore or wound that doesn't heal, or heals and reappears
  • Skin pigment that moves into the surrounding skin
  • Redness, swelling, bleeding, or oozing
  • Any change in how a spot feels, such as itching, or pain, or tenderness
  • A change in the surface such as becoming scaly, or a lump or small bump

Learn more about what to watch for and the ABCDE rule to help you spot possible skin cancer or precancer.

Address Precancerous Skin Cancer Early

Most precancerous growths can be removed by your dermatologist or your general practitioner. If the growth is identified as cancerous, you'll want to be treated by a cancer specialist, also known as an oncologist

Early diagnosis gives you the best chance of a cure, and your oncologist will have more options for your treatment. Untreated growth of a tumor can cause disfigurement that could have been avoided with regular screening and early diagnosis.

Your oncologist may remove the skin cancer by freezing it (cryotherapy), using a special light (photodynamic therapy), or prescribing medication that you apply at home. Treatment can also relieve unpleasant symptoms such as itching or pain. It can improve self-confidence, especially if the growth is in a highly visible place. They will also check to see if the cancer has spread to other areas of the body./p>

Best Ways to Prevent Skin Cancer

The best two ways to avoid skin cancer are limiting your time in the sun and getting regular screenings. 

Residents of the Pacific Northwest Should Never Skip a Skin Cancer Screening

Stay safe and use your sunscreen! Talk with your doctor about your skin and an annual skin cancer check. In the meantime, be on the lookout for anything that might be unusual or new on your skin.

Find More Information on Protecting Yourself From Skin Cancer