Atypical limb pain from a carpal tunnel ganglion cyst

A 29-year-old woman developed left wrist and hand pain following a twisting injury at work. Over the next few weeks she developed constant sharp, stabbing, and aching pain in the dorsal left hand and ulnar forearm. The pain persisted despite medications, splinting, and interscalene blocks. She presented to our specialty pain center one year after symptom onset. Examination revealed tenderness over the dorsal left third metacarpal. Strength, bulk, tone, and reflexes were normal. There was allodynia to vibration at the left cubital tunnel. No other sensory deficits or hyperesthesia were appreciated. Electromyography and nerve conduction studies were entirely normal. Magnetic resonance imaging of the left upper limb revealed a 4 cm x 1 cm volar wrist ganglion cyst. The cyst was excised with excellent relief of pain.

Ganglion cysts in the carpal tunnel are an atypical and rarely reported cause of upper limb pain. This patient's signs and symptoms did not resemble carpal tunnel syndrome, and electrodiagnostic findings were normal. Unusual soft-tissue lesions of the wrist and hand, while rare, must be considered in the differential diagnosis of distal upper limb pain.