An unusual schwannoma of the median nerve: effects on the motor branch.

An unusual case of a schwannoma of the median nerve is presented where pressure due to the tumour on the motor branch to the thenar muscles caused weakness and wasting of the abductor pollicis brevis muscle, a previously unreported phenomenon. The patient achieved a full functional recovery after enucleation, which is also unusual considering the patient's age. Aspects of schwannoma biology, differential diagnosis, investigation and treatment are discussed. Copyright 2001 The British Association of Plastic Surgeons.