💥 Ganglion

🔑 Key Learning

• Common soft tissue lumps of the wrist and hand, usually arising from herniation of the synovial lining.
• Typically asymptomatic, but can cause pain or joint restriction if large.
• Transillumination helps differentiate them from solid masses.
• Most resolve without treatment, but options include aspiration or surgical excision if symptomatic.

🧬 Pathophysiology

• Ganglion cysts arise from outpouching of synovial fluid from a joint capsule or tendon sheath.
• The cyst contains gelatinous synovial fluid and is lined by flattened connective tissue rather than true epithelium.
• Myxoid (mucous) cysts are a subtype typically found near the distal interphalangeal (DIP) joints, associated with osteoarthritis.

👀 Clinical Features

• Common sites:
  • Dorsum of the wrist (most common)
  • Volar aspect of wrist (near the radial artery)
  • Base of the fingers or over DIP joints (in the case of mucous cysts)
• Typically painless, but may cause:
  • Cosmetic concern
  • Local discomfort or aching
  • Restricted joint movement if large or impinging on structures
• On examination:
  • Smooth, round, mobile, cystic swelling
  • Transilluminates due to fluid content
  • Tethered to underlying structures
  • Myxoid cysts may express clear, jelly-like fluid if ruptured

🧪 Investigations

• Diagnosis is clinical
• Ultrasound can confirm cystic nature and differentiate from solid masses
• Imaging may be considered if diagnosis is uncertain or deep cyst suspected (e.g. MRI)

💊 Management

• Reassurance: Most resolve spontaneously
• Conservative:
  • Watch and wait if asymptomatic
• Aspiration:
• • High recurrence rate (~50%)
• Surgical excision:
  • Indicated for:
    • Persistent pain
    • Functional impairment
    • Cosmetic concern with recurrence

📝 Exam Clues & Clinchers

• Transilluminating soft swelling on wrist → Ganglion cyst
• Lump over DIP joint + clear fluid leakage → Myxoid cyst (associated with OA)