A blue–black verrucous nodule

Case presentation

A 72-year-old man presented with a blue–black verrucous nodule on his left temple (Figure 1). The nodule measured 1.5 cm in diameter and had slowly increased in size over 10 years. Dermoscopy revealed a large area of jet-black homogeneous pigment that blended with a series of pale lobules, all covered by a blue–white veil. There was no evident pigment network at the periphery (Figure 2). Excision biopsy showed an eroded epidermis under which there were large lobules of basaloid cells with central pigmentation (Figure 3).