Painless Swelling on Dorsum of Wrist

Painless Swelling on Dorsum of Wrist

This 28-year-old civil servant presented to his family doctor with a painless swelling on the dorsum of his wrist, which he noticed first about a year before. If anything, it was rather larger now and he had recently experienced some aching of the wrist after long sessions on the word processor. He was otherwise perfectly well but was quite worried by this lump and asked to have something done about it.

What’s the diagnosis ?