Alphonsus is a 65-year-old professional violinist who presents with a lump on the radio-volar aspect of the interphalangeal joint of his right thumb.

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Aphonsus is a 65-year-old professional violinist who presents with a lump on the radio-volar aspect of the interphalangeal joint of his right thumb (see picture).

It has been present for six months and is slowly getting bigger. It is uncomfortable and is most noticeable when typing, unscrewing jars and after long orchestral rehearsals.