A skin spot referred to as a “precancerous lesion” is usually a specific sun-induced growth called actinic keratosis. It’s one of the most common issues we see in dermatology, and it’s what prompts most patients to schedule their dermatologist visits to start with.

After years of exposure to UV rays, either from the sun or tanning beds, areas with the most damage start to turn into rough, dry, scaly patches. The patches then develop into thick plaques.

In time, these plaques can progress further until they resemble a horn (called cutaneous horns). These occur on places that receive the most sun damage: forehead, cheeks, nose, tops of the ears, backs of the hands, and forearms.

We see most patients with this condition as the plaques thicken or a cutaneous horn begins to take shape, which are both symptoms of precancerous lesions.

What Does Precancerous Mean?

Think of cancer as a spectrum. On one end, there’s normal, healthy skin. On the other end, there’s malignant, cancerous cells. In the middle, there’s a gray zone — that’s where we find precancerous lesions.

The gray zone is the transformation stage. What we think of as precancerous lesions are actually the development of squamous cell carcinoma (which is malignant). Actinic keratosis is the precursor lesion to squamous cell carcinoma.

Although the transformation rate for each individual lesion is quite low (between 1-5% per year), many people have dozens of actinic keratoses. If each lesion has a 1-5% chance of converting into cancer each year, then at least one of the lesions will likely be cancerous in the future. Once a lesion turns into a carcinoma, it’s a more complicated problem that generally requires surgery.

What Are the Symptoms of Precancerous Lesions?

You can often feel sun-induced growths before you see them. 

A precancerous lesion can be tender and painful. Some patients compare these areas to feeling like fine-grit sandpaper. Others describe it as feeling like a splinter is stuck in their skin when they shave or rub over it.

These types of lesions are also more sensitive. After time in the sun, the lesions become very red and if you shave over them or scratch them, they often bleed.

What Are the Treatment Options for Precancerous Lesions?

There are many treatment options for precancerous lesions (and sun-damage in general). One of the most common ways we treat precancerous lesions in the office is with liquid nitrogen. We freeze the individual lesions during an exam.

Topical chemotherapy creams are another treatment option that can be prescribed for the patient to use at home.

More recently, advances have utilized light therapy for precancerous lesions. Using both blue and red light sources provides another way for us to treat an actinic keratosis in the office.

We can also combine light therapy for precancerous lesions with the benefits of chemical medications. First, we apply a chemical to the skin. Then, the patient sits underneath a light source or laser. The light and chemical combination produces a reaction that kills the precancerous cells.

The right treatment option for you will depend on the number of lesions you have, the area involved, and your desired cosmetic outcome. With all of the options available, we can tailor the treatment plan to your specific needs.

What Should You Expect During Treatment?

When detected early, a precancerous lesion can be successfully treated by your dermatologist using one of several therapy options. In general, you can expect to have minimal discomfort.

Before you visit your dermatologist, always remove any heavy makeup. It makes it easier for us to spot suspicious lesions, and if a procedure is needed that day, your skin is already clean and ready. Otherwise, there’s no specific preparation needed for these treatments.

After your treatment, you may notice a reddening of the skin, small blisters on the sites treated, and scabbing that lasts up to a week. With most cases and treatments, the ultimate cosmetic outcomes are desirable.

FAQs About Precancerous Lesions

I had a precancerous lesion treated last year. Why does it need to be treated again?

The visible evidence of sun damage and precancerous lesions we can detect today are more than likely a result of the sun exposure you had about 20 years ago. If we treat it all today, chances are, I can see you back next year and you’ll have more evidence of precancerous lesions from the sun damage you received 19 years ago.

For every sunburn you’ve had in your life, we expect to see evidence of sun damage and/or precancerous lesions later on in life. Think of it like layers. We can take off a layer of sun damage this year, but you’ll have a new layer that appears next year, too.

What happens if I don’t treat a precancerous lesion?

Precancerous lesions may develop slowly for some time, but the amount of time is unpredictable. Each precancerous lesion has malignant potential. When we identify them, we don’t want to take the risk of waiting to see what happens. We would rather prevent the development of carcinoma and treat these lesions as we find them.

If a precancerous lesion turns into carcinoma, it becomes a much bigger problem. Now you’re facing surgery to treat your cancer. An ounce of prevention is worth a pound of cure.

I wear sunscreen and a hat, so why do I still get actinic keratoses?

The precancerous lesions you see this year are a result of the sun damage you had years ago. These lesions come from a lifetime of sun exposure. At some point, you reach a threshold and begin to develop actinic keratoses.

Keep wearing sunscreen and hats to protect your skin over the remainder of your life – but it won’t undo the damage that was done years ago.

What can I do to prevent the development of actinic keratosis?

We recommend using sunscreen, wearing long-sleeves and hats, seeking shade, and trying to avoid midday sun when possible. Reserve your time outside for the early morning or late evening hours, if possible. Sun exposure causes the development of actinic keratoses, so naturally sun-protection helps prevent it.

Additional Resources

Click here to find an Epiphany provider near you.