Keratoacanthoma

Keratoacanthoma is a rapidly growing, self-resolving, low-grade cutaneous tumour; it is often mistaken for squamous cell carcinoma. It presents as a solitary, dome-shaped nodule with a central keratin-filled crater.

• Signs and symptoms
  • Dome-shaped cutaneous lesion with a keratin plug
    • Rapidly growing – evolves over weeks to months
    • Sun-exposed regions such as the face, neck, and extremities
    • Smooth but may be crusted
    • May ulcerate
    • Multiple lesions may be present in syndromic forms: these include Ferguson-Smith syndrome or Muir-Torre syndrome
• Investigations
  • Biopsy: to rule out squamous cell carcinoma
    • Well-circumscribed, symmetrical lesion witha central keratin plug and crateriform architecture
• Treatment
  • Spontaneously regresses within 3 months
  • Excision may prevent scarring