Cutaneous horn arising from the scrotum

Abstract

A cutaneous horn, cornu cutaneum, is a hard, conical projection composed of compacted keratin that resembles the horns of animals. They commonly occur on sun-exposed areas, including the head, ears, forearms and hands. Cutaneous horns are extremely rare. Although most are benign in nature, a significant portion may harbour a malignant or pre-malignant lesion, and histopathological analysis of the base of the lesion is imperative to categorise it as one of benign aetiology or one of a more sinister pathology. We present a case of a 46-year-old male who presented with a 2-month history of a painless, firm, rapidly growing conical projection arising from his scrotum. Clinically, a non-tender curved, yellow-brown, horn-like projection was observed arising from the median raphe of his scrotum. With informed consent, a full-thickness excision, with adequate excision of the base of the horn, was performed under local anaesthesia. Macroscopically, the exophytic keratinous lesion was 7.5 cm long and 1.8 cm wide, with the length of the horn far outweighing the width at its base. Histopathological analysis confirmed the presence of a cutaneous horn arising from a condyloma acuminatum as evidenced by a verruciform architecture with tiers of parakeratosis in association with hypergranulosis and koilocytes. No dysplastic or malignant changes were present in the epithelium. According to our knowledge, this is the first case in the English literature of a cutaneous horn arising from the scrotal skin.