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Keratoacanthoma on the lip
What is a keratoacanthoma?
A keratoacanthoma is a fairly common benign neoplasm of the skin. It arises mainly in sun-damaged skin. It may mimic squamous cell carcinoma.

Symptoms of keratoacanthoma

A keratoacanthoma starts characteristically at a site of minor trauma of the skin. It starts as a small papule that may mimic a pimple or pustule. The core of an early keratoacanthoma, however, is solid. It typically grows rapidly and it may measure up to 3 cm in diameter in a few weeks time. A typical keratoacanthoma is a dome-shaped papule or volcano-like tumor with a crater filled with keratin.

What is the cause of keratoacanthoma?

Keratoacanthomas probably arise from hair follicle cells. The cells are thought to be triggered to multiply after a minor injury of the skin. After a rapid growth that may continue for weeks to months the tumor will go in self-destruction.


Keratoacanthomas should always be treated. One of the main reasons for this is that it is not always possible to be absolutely sure the lesion is a keratoacanthoma and not a squamous cell carcinoma. Even a pathologist may have problems to differentiate between the benign keratoacanthoma and the malignant squamous cell carcinoma.  Also, the scar which results from treating a keratoacanthoma is in most cases better than if it is left to resolve spontaneously.
Excision is the treatment of choice. Other treatment options are freezing, curettage, cautery and radiotherapy.

Keratoacanthoma arising in naevus
large keratoacanthoma in the face

Further reading on keratoacanthoma


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