A common cause of a cutaneous horn is an actinic keratosis at the base of the horn; a cutaneous horn caused by an actinic keratosis must be distinguished from one arising from a squamous cell carcinoma (SCC), which may be present at the base of a cutaneous horn.
Cutaneous horns most frequently occur in elderly individuals, though they are occasionally seen in children (almost always as warts). In adults, the most common scenario is a cutaneous horn of the face, scalp, or ear presenting with a SCC at the base. Warts and seborrheic keratoses are common benign lesions that may also be seen at the base of a cutaneous horn.
Immunocompromised Patient Considerations:
Immunocompromised patients are prone to SCC, especially on sun-exposed areas, and these may present as cutaneous horns.
Pediatric Patient Considerations:
When cutaneous horns occur in children, a wart is frequently the cause.
L85.8 – Other specified epidermal thickening
403871001 – Cutaneous horn
Differential Diagnosis & Pitfalls