An irregular, dappled, pigmented patch

Case presentation

Over a five-year period, a 54-year-old man developed an irregular pigmented patch (1.9 cm x 1 cm) anterior to his right sideburn (Figure 1). Dermoscopy revealed a light tan lesion with a prominent broad pigment network formed by numerous oval to round flesh-coloured spaces (Figure 2). A central dark hair could be seen in some of the spaces. Skin biopsy showed that the epidermis had broad, pigmented, club-shaped epidermal ridges adjacent to hair follicles (Figure 3). There was no junctional or nested melanocytic proliferation.