A Keratoacanthoma is usually removed as a formal excision which ensures that the lesion is removed in its entirety. A margin of at least 3mm is ideal. Importantly, the whole depth of the lesion is removed and this gives the pathologist the greatest chance of excluding SCC.
Other treatment options may be considered (depending on the circumstance & discussion with the patient) such as curettage and cautery. However, curettage will need to performed deeply in order to ensure the whole depth of the lesion is treated. This wound may take many weeks to heal, another reason why formal excision is usually preferred. Medical treatments include injection of a chemotherapeutic agent.