Carpal tunnel syndrome caused by aberrant lumbrical muscles associated with cystic degeneration of the tenosynovium: a case report.

A 7-year-old boy who suffered from carpal tunnel syndrome caused by aberrant lumbrical muscles associated with cystic degeneration of the tenosynovium of the left hand is described. Judging from the literature studied, this seems to have a very rare origin. Symptoms subsided, and no recurrence has been noticed after operative removal of these structures.