Intraneural ganglion in the digital nerve of the thumb: a case report.

Intraneural ganglion cysts of the peripheral nerve in the upper extremity are uncommon and usually originate within the epineurium of the peripheral nerve. The current report discusses a 57-year-old woman with a neuropathic nodular mass on the thenar area of the left hand. Magnetic resonance images showed a lobulated, homogeneous mass of high signal intensity on T2-weighted images and low signal intensity with peripheral enhancement on T1-weighted images. Excisional biopsy and histopathologic examination confirmed an intraneural ganglion cyst of the digital nerve of the thumb. A successful result was obtained by surgical treatment, and there was no recurrence of abnormal sensation and paraesthesia during the 3-year follow-up period.