Skin Cancer & Precancer
Keratoacanthoma
WHAT IS IT
A fast-growing skin growth, treated as SCC
HOW COMMON
Uncommon; on sun-exposed skin
CONTAGIOUS?
No — you cannot catch it or spread it
CURABLE?
Yes — usually cured with removal
What Is It?
A keratoacanthoma is a rapidly growing, dome-shaped skin bump with a central plug of keratin, giving it a crater-like or "volcano" look. It grows quickly over weeks. Although some can shrink on their own, it can be hard to tell apart from squamous cell carcinoma, so it is usually treated like a skin cancer.
Signs & Symptoms
-
A rapidly growing, firm, dome-shaped bump
-
A central crater filled with keratin (like a plug)
-
Pink or skin-colored, sometimes tender
-
Grows noticeably over just a few weeks
-
Common on the face, arms, and backs of the hands
Why Does It Happen?
Keratoacanthomas are linked to sun (UV) damage and are most common on sun-exposed skin. Injury to the skin, certain medications, and genetic factors can also play a role. Because it closely resembles squamous cell carcinoma under the microscope, it is taken seriously and removed. It is NOT contagious.
Treatment Options
Because it can't be reliably separated from squamous cell carcinoma, a keratoacanthoma is usually removed and examined. Prompt treatment is recommended.
SURGICAL REMOVAL
Cutting out the growth to treat it and confirm the diagnosis.
BIOPSY FIRST
Sampling may be done to guide the best treatment approach.
INJECTED MEDICINE
For select or multiple lesions, injected treatments are sometimes used.
FOLLOW-UP
Monitoring the site and skin for new or recurrent growths.
Tips for Managing It at Home
-
Have any fast-growing bump checked promptly — don't wait it out
-
Use daily sun protection to reduce future lesions
-
Do regular skin self-checks and report new growths
-
Keep follow-up appointments after treatment
When to Call Your Provider
-
A bump grows rapidly over weeks
-
A growth bleeds, ulcerates, or won't heal
-
A new firm bump appears on sun-exposed skin
-
The area recurs after previous treatment
Sources & further reading
The information in this handout is based on general dermatology guidance from the reputable organizations below. These links are provided for patients who wish to read more from trusted sources.
DermNet. Keratoacanthoma. https://dermnetnz.org/topics/keratoacanthoma
Canadian Dermatology Association (CDA). Squamous Cell Carcinoma. https://dermatology.ca/public-patients/diseases-conditions/skin-cancer/squamous-cell-carcinoma/
MSD/Merck Manual. Squamous Cell Carcinoma. https://www.msdmanuals.com/professional/dermatologic-disorders/cancers-of-the-skin/squamous-cell-carcinoma
Cleveland Clinic. Keratoacanthoma. https://my.clevelandclinic.org/health/diseases/keratoacanthoma
This handout is for general education and does not replace advice from your own provider. Always follow your provider’s specific instructions.
← Back to all handouts