Pyogenic granuloma simulating a cutaneous horn.

A cutaneous horn is a keratotic, usually conical tumor, consisting of a spire of accumulated, cohesive stratum corneum. A number of primary lesions underlying the horny material are known to cause this condition. We present an unusual case of pyogenic granuloma clinically mimicking a cutaneous horn and suggest that it be included in the initial differential diagnosis as a rare cause of this entity. We also review various known causes of cutaneous horn.