summary Ganglion Cysts are mucin-filled synovial cysts and are the most common masses found in the wrist and hand. Diagnosis can be made clinically with a firm and well circumscribed mass that transilluminates. Treatment can be observation for majority of ganglions. Surgical excision is indicated for ganglion cysts associated with severe symptoms or neurovascular manifestations. Epidemiology Incidence common login to view 1 more bullet Anatomic location dorsal carpal (70%) login to view 1 more bullet volar carpal (20%) login to view 1 more bullet volar retinacular (10%) login to view 1 more bullet dorsal DIP joint (mucous cyst, associated with Heberden's nodes) may also occur in the lower extremity login to view 1 more bullet Etiology Mechanism trauma mucoid degeneration synovial herniation Pathophysiology filled with fluid from tendon sheath or joint no true epithelial lining Associated conditions median or ulnar nerve compression login to view 1 more bullet hand ischemia due to vascular occlusion login to view 1 more bullet Presentation Symptoms usually asymptomatic may cause issues with cosmesis Physical exam inspection login to view 1 more bullet palpation login to view 2 more bullets vascular exam login to view 1 more bullet Imaging Radiographs normal MRI indications login to view 1 more bullet findings login to view 1 more bullet Ultrasound useful for differentiating cyst from vascular aneurysm may provide image localization for aspiration while avoiding artery Histology Biopsy indications login to view 1 more bullet findings login to view 1 more bullet Treatment Nonoperative observation login to view 4 more bullets closed rupture login to view 2 more bullets aspiration login to view 5 more bullets Operative surgical resection login to view 7 more bullets Complications With aspiration infection (rare) neurovascular injury With excision infection neurovascular injury (radial artery most common) injury to scapholunate interosseous ligament stiffness