Carpal tunnel syndrome caused by a fibrolipomatous hamartoma of the median nerve treated by endoscopic release of the carpal tunnel.

Fibrolipomatous hamartoma has up to now been considered a rare anomaly that most commonly affects the median nerve. Its pathogenesis is controversial. The magnetic resonance (MR) appearance is pathognomonic and precludes the necessity for a diagnostic biopsy. Its reported incidence is likely to increase as a result of the increased use of MRI. There is no definitive treatment, although carpal tunnel syndrome caused by fibrolipomatous hamartoma has been noted to respond to open release of the carpal tunnel. We describe a case of carpal tunnel syndrome caused by fibrolipomatous hamartoma of the median nerve that responded to a two-port endoscopic technique of release. Provided that a safe, distinct surgical plane can be established between the median nerve and the flexor retinaculum, the two-port technique of endoscopic release of the carpal tunnel is both safe and effective.