This patient information and photograph on Keratoacanthoma/Squamous Cell Cancer is provided by John L. Meisenheimer, M.D. a board certified Dermatologist and skin care specialist based in Orlando, Florida. This information is not intended as a substitute for the medical advice or treatment of a dermatologist or other physician.
What is it? keratoacanthoma/Squamous cell carcinoma is a specific type of skin cancer. It can occur at any age, but it appears more often in adults over 60. Typically it will appear on sun damaged skin as a thick growth that has a central crusted plug that may look like a horn. Its color may vary from skin color to pink or red. Sometimes there may be a central crater like crust instead of a horny plug. Keratoacanthoma is considered by most dermatologists to be a subtype of Squamous cell cancer. Keratoacanthomas can grow very rapidly sometimes reaching more than a inch in diameter in two to three weeks time. There are rare types of keratoacanthomas that can grow to an extremely large size, sometimes 8 to 20 inches in diameter, these are called giant keratoacanthomas. Keratoacanthomas are unusual in that many will clear spontaneously on their own in 4 to 6 months, but because some can be very aggressive most are treated like any other squamous cell skin cancer.
What causes it? The exact cause of keratoacanthoma/squamous cell carcinoma is unknown. I would like to emphasize that ultraviolet radiation from sun exposure is the biggest risk factor. Even if you never were out in the sun much, decades of going to the mailbox, hanging laundry, etc... all tally up for a significant amount of sun exposure. The effects of your sun exposure are cumulative. People at highest risk are those who have fair skin, light colored eyes, and have spent a lifetime working in the sun.
Regular use of sunscreen has been shown to decrease risk for the development of squamous cell skin cancer. My personal recommendation is a waterproof sunscreen with an SPF of 30 or higher Sunscreen Info./Ordering For more skin care in the sun recommendations click here sun skin care.
How is it treated? There are several different ways this cancer can be treated and I will discuss the options with you. I adapt the treatment to fit the individual problem considering what will give the highest cure rate with the best cosmetic result.
Is it dangerous? Yes, unless treated. If neglected, this cancer will continue to grow. On rare occasions this cancer can spread to other organs and even be fatal.
Can it grow back? A small number may re-grow even after treatment and will need further treatment. Individuals that have had one keratoacanthoma/squamous cell carcinoma are much more likely to get another compared to the general population. Periodic follow up is needed to check for any signs of re-occurrence or development of new cancers.
Will I get more? People that have one keratoacanthoma/squamous skin cancer are at higher risk to get more. There are some rare patients that may get hundreds over a lifetime. I cannot emphasize enough the importance of regular skin exams in those that have a history of keratoacanthoma/squamous cell carcinoma. You should become aware of the signs and symptoms of skin cancer and point out to me any suspicious new growths that may occur.
Is it contagious? Squamous cell cancer is not contagious and you can not "catch it" from anyone.