A cutaneous horn, also known as keratoacanthoma, is a benign tumour of the skin.
It appears more frequently in Caucasian males over 50 years old and in areas of the skin exposed to the sunlight (e.g. face, neck and upper limbs). In addition to UV light, some cases have been reported to be associated with papillomavirus or chemical carcinogens (e.g. pitch and coal), as well as immunosuppression and genetic factors.
It usually consists of a single lesion of 1-2.5 cm in size, although they may be more or be larger. They appear as a dome that grows rapidly on the skin and has a central crater.
The diagnosis is made by doing an examination and a biopsy of the lesion.
The most frequent is spontaneous remission in less than six months after its onset, leaving a hypopigmented scar. The most suitable approach is a surgical excision with a subsequent study to rule out the possibility of it turning malignant. Curettages, daily application of a 5-fluorouracil cream or a corticosteroids and/or bleomycin infiltration may be performed.
- Tran DC, Li S, Henry AS, et al. An 18-year retrospective study on the outcomes of keratoacanthomas with different treatment modalities at a single academic center. Br J Dermatol 2016.
- Browne F, O'Connell M, Merchant W, et al. Spontaneous resolution of a giant keratoacanthoma penetrating through the nose. Clin Exp Dermatol 2011; 36:369.
- Ko CJ. Keratoacanthoma: facts and controversies. Clin Dermatol 2010; 28:254
- Karaa A, Khachemoune A. Keratoacanthoma: a tumor in search of a classification. Int J Dermatol 2007; 46:671.
- Schwartz RA. Keratoacanthoma: a clinico-pathologic enigma. Dermatol Surg 2004; 30:326.

