Triggering of Thumb by a Ganglion Cyst of the Flexor Tendon Sheath at A1 Pulley: A Case Report

INTRODUCTION: Ganglions of the wrist and hand are commonly seen but the most common sites are in the dorsum of the wrist followed by the volar side in the distal forearm at the wrist crease. The Ganglion cysts arising from the flexor tendon sheath are rare and only a few are reported in the literature. CASE REPORT: We report a rare case of a ganglion cyst of the flexor tendon sheath at A1 pulley of thumb in a 35-year-old male who came with the complaint of chronic triggering of the left thumb. The histopathological examination confirmed the ganglion which was removed from the A1 pulley area. CONCLUSION: A1 pulley ganglion causing trigger thumb is uncommon entity. Although, traditional treatment for this is conservative or aspiration. High recurrence is observed. When it comes to preservation of fine movements such as thumb, aggressive approach involving exploration and excision of cyst gives good functional outcome and reduces chance of recurrence.