Compression of the radial nerve at the elbow by a ganglion: two case reports.

INTRODUCTION: Radial nerve compression by a ganglion in the radial tunnel is not common. Compressive neuropathies of the radial nerve in the radial tunnel can occur anywhere along the course of the nerve and may lead to various clinical manifestations, depending on which branch is involved. We present two unusual cases of ganglions located in the radial tunnel and requiring surgical excision.

CASE PRESENTATION: A 31-year-old woman complained of difficulty in fully extending her fingers at the metacarpophalangeal joint for 2 weeks. Before her first visit, she had noticed a swelling and pain in her right elbow over the anterolateral forearm. The extension muscle power of the metacarpophalangeal joints at the fingers and the interphalangeal joint at the thumb had decreased. Sonography and magnetic resonance imaging of the elbow revealed a cystic lesion located at the area of the arcade of Frohse. A thin-walled ovoid cyst was found against the posterior interosseous nerve during surgical excision. Pathological examination was compatible with a ganglion cyst. The second case involved a 36-year-old woman complaining of numbness over the radial aspect of her hand and wrist, but without swelling or tumor in this area. The patient had slightly decreased sensitivity in the distribution of the sensory branch of the radial nerve. There was no muscle weakness on extension of the fingers and wrist. Surgical exposure defined a ganglion cyst in the shoulder of the division of the radial nerve into its superficial sensory and posterior interosseous components. There has been no disease recurrence after following both patients for 2 years.

CONCLUSION: Compression of nerves by extraneural soft tissue tumors of the extremities should be considered when a patient presents with progressive weakness or sensory changes in an extremity. Surgical excision should be promptly performed to ensure optimal recovery from the nerve palsy.