An Unusual Schwannoma in the Proximal Forearm: A Case Report.

Schwannomas are common, well-encapsulated benign tumors of the peripheral nerves. They rarely emerge from the median nerve in the forearm. Here we report a case of an unusual schwannoma measuring 3 × 4 × 3 cm originating from the median nerve in the proximal forearm of a 49-year-old man. The mass was painless, but Tinel's sign was positive. Ultrasonography showed a solid, hypoechoic mass with central cystic areas in the flexor muscle group in the left forearm. Magnetic resonance imaging with contrast enhancement in T1 sequences revealed that it originated from the median nerve. Surgical resection was performed by separating the nerve fibers from the tumor without any complications. Histological examination confirmed it as a schwannoma.