Keratoacanthomas begin as a smooth, dome-shaped, red papule. Lesions grow rapidly.

Keratoacanthomas develop and grow rapidly, forming a keratin-filled necrotic crater.

This lesion resembles both a keratoacanthoma and a squamous cell cancer, which is typical of advancing keratoacanthomas. It is best to treat this lesion as a squamous cell carcinoma.

Keratoacanthomas are dome-shaped tumors with a central crateriform crust that grows rapidly. Typical locations include the face, neck, hands and sun-exposed extremities.