Cutaneous Horn

A cutaneous horn, or cornu cutaneum, is a relatively uncommon, hyperkeratotic epithelial lesion resembling an animal horn, characterized by a height more than half of the diameter of its base. The first formally documented case originates from the 1588 description of an elderly Welsh woman, Margeret Gryffith. Her disease and subsequent exploitation in circuses profiting from medical oddities spurred the term "horned people" in popular culture. It wasn't until the mid-17th century that this misconception was debunked by Danish anatomist Thomas Bartholin, who described these horny growths as a tissue tumor arising from the surface of the skin. Cutaneous horns are now widely accepted as reactive cutaneous growths caused by various benign, premalignant, or malignant primary processes. The cutaneous horn lesion is usually evident upon physical examination and can be described as a white or yellow exophytic protrusion in the shape of an animal horn. Unlike animal horns that generally contain an osseous cast, cutaneous horns consist solely of cornified proliferative keratinocytes without a bony component. The color, size, shape, and dimensions can vary significantly, so histopathological analysis should confirm clinical suspicion. Although the prevalence and incidence of cutaneous horns have not been established, epidemiological conclusions have formed correlations with age, sex, skin color, location, and dimensions. Histopathological evidence asserts the cutaneous horn is relatively unimportant compared to its underlying condition. Consequently, understanding the etiology and associated histopathology behind cutaneous horns has been among the primary concerns of clinicians and researchers.