A very large Schwannoma originating from the median nerve in carpal tunnel.

Schwannomas are common benign nerve tumors occurring in the peripheral nerves. A very large schwannoma of more than 5 years duration, originating from the median nerve in the carpal tunnel in a 38-year-old woman, is reported. There was a painful mass, 60 mm in length and 42 mm in diameter, on the palm without signs of sensory disturbance or atrophy on the thenar muscles. Surgical removal was performed under high-power magnification by separating the sensory and motor fascicles from the tumor. Histological examination resulted in a Schwannoma. At 4-year follow-up, the patient was asymptomatic with excellent relief of symptoms. The tumor did not recur. Although cases have been reported in the literature, this is one of the largest ever described without any neurologic deficit.