What is a cutaneous horn?
Cutaneous horns were given their name due to resemblance of an animal horn. These lesions are rough, hard growths that protrude from the skin and can vary in size, shape and color. Cutaneous horns can arise from precancerous or benign lesions. Those arising from solar/actinic keratoses usually arise in body parts that receive chronic sun exposure such as the ears, face, tops of hands, forearms and shins. Cutaneous horns arising from benign lesions, such as warts or seborrheic keratoses, can form anywhere on the body.
How is a cutaneous horn formed and who is at risk?
Cutaneous horns are the result of increased cell division leading to “hyperkeratosis.” Hyperkeratosis is the thickening of the top layer of the skin. This leads to formation of a dry, rough growth on the surface of the skin. Factors that increase risk of development include older age, chronic sun exposure, presence of precancerous lesions and lighter skin types.
How is a cutaneous horn treated?
Cutaneous horns that arise from precancerous lesions should be treated with cryotherapy, surgical excision or topical chemotherapy. Those that arise from benign lesions may be left alone if asymptomatic, but can be removed with cryotherapy and surgical excision.
Figure 1: Cutaneous horn on the helix of the ear.
Wolff K, Johnson, RA. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. Sixth Edition. 2009.