Ganglion cyst

Section: Skin and soft tissue Sub-section: Benign skin and soft tissue Curriculum: Curriculum, page 52

Definition

• Mucin-filled synovial cysts

Incidence

• Most common cause of focal masses in the hand

Clinical

• Usually firm, round, often tender cystic mass – full of slightly thickened synovial fluid
• Causes aching, feeling of weakness
• Can disappear spontaneously but sometimes recur

Aetiology

• Mechanism
  • Trauma
  • Mucoid degeneration
  • Synovial herniation
• Probably recurrent injury
  • Leading to disruption of joint capsule and herniation of synovium
  • Arise from synovium of joints or tendon sheaths or tendons
  • Most frequent is Dorsal Scapholunate Ligament (80%)
    • Palpated between 2nd and 4th extensor tendon compartments
  • 2nd most frequent is volar just radial to flexor carpi radialis tendon (Scaphotrapezoid Joint)
  • Most common site in flexor tendon is at level of MCP joint flexor skin crease

Diagnosis

•  Can be made clinically with a firm and well circumscribed mass that transilluminates.

Treatment

• Non-operative
  • First line
• Closed rupture
  • High recurrence
• Aspiration
  • Second line
    • High recurrence 50%
• Surgical excision
  • Incision directly over lump (transverse for dorsal, longitudinal for volar), dissect out cyst
  • Follow down to neck and excise with generous capsule around cyst base
  • Cauterise capsule edge
  • Do not close joint capsule
  • Close skin
  • Arthroscopy increasing in role
  • Prognosis with surgery: Recurrence = 5-10%