A giant cutaneous horn.

A cutaneous horn is a uncommon and rare lesion. It is a conical projection of hyperkeratotic epidermis. Vary from a few milimeters to a several centimeters in length. The cutaneous horn is a clinical diagnosis and different histologic lesions have been documented at the base of the keratin mound. We presented a 77 years old female with a large "horn" of 3 years duration, arising from her forehead. Excision was performed and defect was covered by split thickness skin graft. Hystopathology reported keratoacanthoma at the base of the horn. By reviewing cutaneous horns presented in literature we can declare that this is one of the biggest cutaneous horn recorded cases. Also it is important to mention that horn itself is not the most important issue, but rather the underlying condition, which may be malignant.