Acquired Digital Fibrokeratoma

Abstract

Acquired digital fibrokeratoma is a rare, benign tumor that mostly occurs on the fingers and toes and may appear to be a supernumerary rudimentary digit. It generally affects adult men and appears as a dome-shaped papule although it can also be elongated or pedunculated. Trauma is believed to be a triggering factor in some cases. We report a male patient with an acquired digital fibrokeratoma on a finger, shaped like a cutaneous horn, and a history of minimal repeated trauma and spontaneous remissions not previously described in the literature.

Keywords: acquired digital fibrokeratoma; acquired fibrokeratoma; cutaneous horn; occupational diseases; occupational pathology.

Figure 1. Clinical photograph

Upon examination, the lesion presented like a 1 cm long cutaneous horn, emerging from a hyperkeratotic collarette.

Figure 2. Histopathological photographs

(A) H&E 40x. Dermal proliferation composed of dense collagen fibers (oriented predominantly in the vertical direction) and blood vessels covered by keratinizing mature squamous epithelium with papillomatosis (yellow arrows) and marked compact hyperkeratosis (white arrows). Both neural and adnexal structures absent. (B) H&E 200x. Hypergranulosis (green arrows) and thin-walled capillaries and simple endothelium with congestion within dermal papillae. Thickened collagen within the dermis oriented predominantly in the vertical direction.