Keratoacanthoma is a benign epithelial tumour. They are more common with advancing age and rare in young people.

Features - said to look like a volcano or crater

• initially a smooth dome-shaped papule
• rapidly grows to become a crater centrally-filled with keratin

Spontaneous regression of keratoacanthoma within 3 months is common, often resulting in a scar.

Such lesions should however be urgently excised as it is difficult clinically to exclude squamous cell carcinoma. Removal also may prevent scarring.