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 most common hand mass (60-70%) Anatomic location dorsal carpal (70%) originate from SL articulation volar carpal (20%) originate from radiocarpal or STT joint volar retinacular (10%) originate from herniated tendon sheath fluid dorsal DIP joint (mucous cyst, associated with Heberden's nodes) may also occur in the lower extremity most commonly about the knee 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 may be caused by volar ganglion hand ischemia due to vascular occlusion may be caused by volar ganglion Presentation Symptoms usually asymptomatic may cause issues with cosmesis Physical exam inspection transilluminates (transmits light through tissue) palpation firm and well circumscribed often fixed to deep tissue but not to overlying skin vascular exam Allen's test to ensure radial and ulnar artery flow for volar wrist ganglions Imaging Radiographs normal MRI indications not routinely indicated findings shows well marginated mass with homogenous fluid signal intensity Ultrasound useful for differentiating cyst from vascular aneurysm may provide image localization for aspiration while avoiding artery Histology Biopsy indications not routinely indicated findings will show mucin-filled sac with no true epithelial/synovial lining Treatment Nonoperative observation indications login to view 3 more bullets closed rupture home remedy high recurrence aspiration indications login to view 2 more bullets outcomes login to view 1 more bullet Operative surgical resection indications login to view 1 more bullet technique login to view 2 more bullets results login to view 1 more bullet Complications With aspiration infection (rare) neurovascular injury With excision infection neurovascular injury (radial artery most common) injury to scapholunate interosseous ligament stiffness