Facial lesion that came “out of nowhere”
Diagnosis: Cutaneous horn
Cutaneous horn,also referred to as cornu cutaneum, is a clinical (morphologic) diagnosis, not a precise pathologic diagnosis. It describes an asymptomatic, projectile, conical, dense, hyperkeratotic lesion that resembles the horn of an animal.
Cutaneous horns can arise from a variety of primary underlying pathologic processes, including benign, premalignant, and malignant lesions. Thus, the important issue when confronted with a cutaneous horn is determining the causative pathologic process. Therefore, for treatment, most authors stress surgical excision with attention to removing the base of the specimen for histopathologic examination.1-4
Cutaneous horns may vary considerably in size and shape. Most are a few millimeters in length, but there are reports of some measuring up to 6 cm in length. They may be perpendicular or inclined in relation to the underlying skin. They usually occur singly and may grow slowly over decades.2,4
Cutaneous horns are more common in older and white individuals, although they have been reported in children and African Americans.5The higher prevalence in older and light-skinned individuals is secondary to the fact that many cutaneous horns are caused by cumulative sun damage over many years, leading to actinic keratoses and nonmelanoma skin cancer.
