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

This image shows a dome-shaped, skin-coloured to erythematous nodule with a central keratin-filled crater, characteristic of a keratoacanthoma. The lesion has a smooth, shiny surface and appears well-circumscribed, arising rapidly over a few weeks. Keratoacanthomas are low-grade, well-differentiated squamous cell neoplasms, often considered a variant of squamous cell carcinoma (SCC).

Keratoacanthoma

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.