A 72-year-old man consulted for a rapidly enlarging tumor on his right forearm. The lesion appeared 3 to 4 months before.
The main clinical diagnosis was a keratoacanthoma.
Dermoscopy revealed:
- a central brownish structureless area corresponding to a central mass of keratin
- a whitish area with presence of elongated hairpin vessels
A central brownish structureless area (black circle) and hairpin vessels on a whitish background (white circle) are the two main dermoscopic signs in favor of a keratoacanthoma.
The diagnosis was confirmed by pathology after the complete excision of the tumor.
