Actinic keratosis underlying cutaneous horn at an unusual site-a case report

Abstract

Cutaneous horns are usually found on chronic sun-damaged skin. A cutaneous horn is a rare tumour, often conical, circumscribed, and composed of dead keratin usually derived from base keratinocytes. It occurs mainly in association with underlying benign, premalignant, and malignant cutaneous diseases. The commonest malignancy is squamous cell carcinoma. Thus, to accurately ascertain the nature of the condition at the base of the lesion and to rule out malignancy, an excision biopsy is indicated. Here, we report a case of cutaneous horn over the palmar aspect of the left middle finger in a 45-year-old man whose histopathology showed actinic keratosis.

Keywords: actinic keratosis; cornucutaneum; cutaneous horn.

Figure 1:. A horny growth of around 2 cm in length with a broad base over the palmar aspect of the middle phalanx of the left middle finger.

Figure 2:. (a) Hyperkeratosis and focal parakeratosis, Hematoxylin & Eosin (H & E) stain 4x; (b) loss of polarity and disordered arrangement of keratinocyte in stratum malphigian with part of normal dermis, H & E stain 10x.