Gouty tophus causing tarsal tunnel syndrome.

Tarsal tunnel syndrome (TTS), first described in 1962, has been associated with a variety of causes, including trauma, neurilemomas, rheumatoid arthritis, and hypothyroidism. We report the first case of TTS caused by a tophaceous mass in the tarsal tunnel and review etiologies, clinical descriptions, and diagnostic studies for TTS. We also survey pseudotumor crystal-induced lesions and descriptions of tophi in unusual sites.