Cutaneous horn is a descriptive rather than diagnostic term that refers to horn projections of tissue that are caused by a variety of neoplasms, including actinic keratosis, warts, Bowen disease, granular cell tumors, Paget disease, sebaceous neoplasms, basal and squamous cell carcinoma, and seborrheic keratosis.1 Rarely, molluscum contagiosum of the poxvirus group forms a cutaneous horn. The only other infectious cause is leishmaniasis. Cutaneous horns are removed by shave biopsy and the tissue is sent for histologic examination.
1. Hoffman PC, Lenet MD, Sherman M. Cutaneous horns: review of literature and case report. J Foot Surg.1988;27:130-133.