Hello

Precancerous lesions and moles are ones which have the potential to become cancerous over time.  Our Doctor Kevin Berman talks about precancerous moles and freckles.

Here is another article by Dr. Berman about precancerous moles and other lesions.  Here is what he says about the most common type of precancerous lesion:  "The most common "precancerous" skin lesion is an "actinic keratosis", which is a sun-damaged area of skin that usually appears as a red and scaly patch of skin. Because it is caused by sunlight, the most common location for actinic keratoses is the face, ears, scalp, arms, upper back, and upper chest. These lesions are labeled as being "precancerous" because without treatment, a small percentage of these lesions develop into squamous cell carcinoma, which can be a very invasive skin cancer."

And here is what Dr. Berman says about precancerous moles:  "The other commonly treated precancerous lesion is the "dysplastic nevus", also known as an atypical mole. These lesions are usually brown or black moles which are biopsied due to having suspicious features of melanoma, such as irregular borders or asymmetry or having multiple colors. While not cancerous, these lesions are also clearly different from harmless, benign moles. These atypical moles have the potential to develop into melanoma, which is why it is advisable to have any changing or growing mole checked as it may be atypical and changing into a cancerous lesion."

So when a mole or lesion is said to be precancerous...this means that there is a chance over time that it will become cancer.

Here is our information page about the different types of skin cancer. 

And here is even more information about precancerous moles and lesions and skin cancer from the American Cancer Society.

I hope this helps some.  Thank you for your question.