A male patient of Asian origin, with light to medium brown skin, presented with a new, solitary pigmented lesion on his back. As far as he could remember, it had developed over about six months. There was no previous history of skin disease and he was in good general health, with no significant personal or familial medical problems or medication.

Inspection revealed a deeply pigmented raised lesion about 6mm in diameter on his upper back. It was firm to the touch, the centre slightly depressed, and light adherent scale was present. There were no other lesions on the rest of the skin.

Dermoscopy was not reassuring, revealing a chaotic pattern of dots and globules (clods) of varying sizes. Fine radial streaks were seen at several points of the periphery. There were no features of a benign lesion, such as haemangioma, dermatofibroma, seborrhoeic keratosis or benign naevus.