Bowen's disease of the nail bed.

A 77-year-old man presented with a 2-year history of left thumbnail dystrophy, purulent discharge and aching pain. There was no history of trauma. On examination there was a linear area of nail dystrophy and dyschromia of the nail bed. The nail plate was thinned proximally. No other digits were affected. There was no lymphadenopathy. X-ray of the digit was normal. Longitudinal nail biopsy revealed Bowen's disease along the length of the nail bed and nail matrix specimen. After avulsion of the nail plate, the nail matrix and tumour were fully excised. The defect was repaired with a split-skin graft. His symptoms were relieved.