What is a Keratoacanthoma
(Also known as: KA, kerato-acanthoma, crateriform carcinoma, pseudo-squamous carcinoma)
A keratoacanthoma is a rapidly growing skin lesion that originates from keratinising cells in a hair follicle. The lesion typically grows over a matter of weeks from a slight bump into a dome-shaped nodule with a central keratin "plug" or crater-like core, giving a volcano-like appearance. If untreated, it may regress, but it is often removed because it resembles a type of skin cancer.
Key Identifying Features
Keratoacanthoma appear as a single lesion in most cases, arising on sun-exposed skin and typically presents as:
- A skin-coloured to pinkish papule (initially small) that enlarges rapidly (weeks).
- Then becomes a firm, smooth-shouldered dome-nodule, often 1–2 cm (or more) across, often with a crater filled with a yellow-brown keratin/horn plug.
Because its appearance and behaviour overlap with Squamous Cell Carcinoma (SCC), the diagnosis is often treated with caution; some lesions may, in fact, represent SCC.
Where They Commonly Occur
- Face (cheeks, nose, temples)
- Forearms and backs of hands
- Occasionally, lower legs or other sun-exposed sites
Contributing Factors
- Chronic sun (ultraviolet) exposure - particularly to skin already sun-damaged.
- Fair skin / lighter skin phototype, and older age groups.
- History of skin injury or trauma to the area (the “koebner” effect) or skin that has been damaged.
- Suppressed immune system, for example, transplant recipients and immunosuppressed patients may be at increased risk.
- Use of certain medications (e.g. some melanoma treatments) has been linked in case series.
Prevalence
While exact UK population rates are hard to define, keratoacanthomas are more common in middle-aged or older adults (often over age 60), more common in fair-skinned people and men than women.
Treatment Options
At Cambridge Contour Clinic, we offer the following professional medical-grade treatment options for Keratoacanthoma:
Micro-Plasma Removal
We use a surgical-grade micro-plasma device, which creates a precise plasma arc (~0.02 mm accuracy) to vaporise the lesion tissue.
Cryotherapy
Using a fine jet of N₂O under high pressure, we freeze the lesion with millimetre precision.
Which is most suitable for you is best discussed within a consultation with one of our specialists, where they will discuss your treatment options, check you are able to have said treatments (i.e there are no health contraindications). They will also discuss healing and success rates, check that you are happy with any potential risks and address any necessary pre- and post-care, treatment plans and pricing.
Other potential treatment options
Here at Cambridge Contour Clinic, we focus on minimally invasive techniques to optimise healing and cosmetic outcomes. However, we believe in transparency to help our clients make an informed choice on how they would like to proceed. Therefore, if we are aware of other recognised treatment methods that may be suitable for you, we will discuss these during your consultation.
Prevention
- Use broad-spectrum sunscreen daily on sun-exposed skin.
- Avoid prolonged sun exposure, especially at peak times; wear protective clothing.
- Monitor your skin for new bumps or changes (size, colour, shape, bleeding).
- If you have a history of skin damage, immunosuppression, or many sunspots, discuss a regular dermatology review.
When to See a Specialist
Although a keratoacanthoma in itself may regress, it is very important to get any rapidly-growing lesion checked because of the overlap with squamous cell carcinoma. If you notice a new rapidly growing bump, one that changes, bleeds, or persists, you should consult a dermatologist or your GP and ask for a specialist skin review.
Keratoacanthoma Frequently Asked Questions
Is a keratoacanthoma a cancer?
Keratoacanthoma is generally considered a benign lesion, but it can look and behave similarly to squamous cell carcinoma (SCC).
What happens if I leave it untreated?
Some keratoacanthomas will regress on their own in 3-6 months (or longer). However, because they may leave a deep scar, most are removed.
Can the lesion come back?
If completely removed, recurrence is rare. However, partial removal has a higher recurrence risk.
