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A 22-year-old man presented with a pigmented lesion on the glans penis, which had occurred 6 years previously and had been slowly growing in size. Physical examination showed a dome-shaped dark brown nodule, 9 mm in diameter, with a pinkish erythema in the centre of the glans penis (Fig. 1). An excision biopsy was made, and histological examination of a magnified portion of the upper dermis revealed spindle cells grouped within demarcated nests and epithelioid cells grouped within poorly demarcated nests (Fig. 2). The tumour cells were relatively uniform in size and showed no atypia. Eosinophilic globules at the dermal – epidermal junction, Kamino bodies, were observed. Immunohistochemical analysis demonstrated that the cytoplasm of the tumour cells was positive for S-100 protein, but not for HMB-45 (Dako Cytomation, Kyoto, Japan). Only 0.2% of tumour cells were positive for Ki-67 (MIB-1, Dako Cytomation) and proliferating cell nuclear antigen (PC10, Dako Cytomation). These findings strongly suggested that the tumour was a Spitz naevus (1). Over the 2 years and 5 months since the excision, there has been no sign of any recurrence.