A ganglion cyst is a benign, fluid-filled swelling that arises in relation to a joint capsule, tendon sheath, or synovial sheath, commonly presenting near the wrist or fingers. These cysts contain gelatinous, mucinous fluid and are often likened to a water balloon on a stalk.
Common Locations
- Dorsal wrist (most common site)
- Volar (palmar) wrist
- Base of the fingers (palmar side)
- Dorsum of the distal interphalangeal (DIP) joint — often associated with mucous cysts and osteoarthritis
🧬 Pathogenesis
- Cystic degeneration of connective tissue around tendons or joints
- Synovial fluid herniation through weakened joint capsules or tendon sheaths
- Coalescence of microcavities within the synovial sheath, forming a visible cyst
Though the exact etiology is unknown, contributing factors include:
- Repetitive trauma or irritation
- Joint or tendon overuse
- Degenerative joint disease (esp. in older adults with mucous cysts)
🩺 Clinical Features
- Well-defined, round or oval swelling
- Smooth, cystic, or tensely cystic consistency
- Non-tender and fluctuant
- Transilluminant (transmits light)
- Mobile, but restricted when associated tendon is activated against resistance
- May be associated with pain, tenderness, or limited joint motion in some cases
💡 Paget’s Test Positive: Firm swelling becomes more prominent or tense with joint use or resistance.
🧾 Differential Diagnosis
- Lipoma – soft, non-cystic, non-transilluminant
- Lymphatic cyst – may be soft and compressible
- Sebaceous cyst – has a punctum and thicker content
- Bursa – may appear near joints, often larger and softer
- Sesamoid bone or exostosis – hard, immobile, bony on palpation (small ganglia may mimic these)
🧪 Diagnosis
Primarily clinical, based on:
- Typical location and characteristics
- Transillumination test: cyst glows under light
- Palpation: soft to firm, well-localized mass
Imaging studies (when needed):
- X-rays: rule out bony pathologies like arthritis or osteophytes
- Ultrasound: confirms cystic nature; distinguishes from solid masses
- MRI: detects occult ganglia or complex cysts not visible clinically
💊 Treatment
🔹 Conservative (First-Line)
- Observation: Indicated in asymptomatic cases due to high rate of spontaneous resolution
- NSAIDs: For pain control in symptomatic patients
- Immobilization: May reduce swelling by limiting activity (use sparingly)
🔹 Minimally Invasive
- Aspiration:
- Simple, office-based procedure
- May be combined with corticosteroid injection
- High recurrence (~50%)
- Sclerotherapy: Less commonly used; not as effective
🔹 Surgical Excision
- Indicated for:
- Persistent pain
- Functional impairment
- Cosmetic concerns
- Performed under local anesthesia (2% lignocaine plain)
- Important to excise:
- Entire cyst
- Stalk
- Associated joint capsule if necessary
- Recurrence rate: ~30%
- Post-op care:
- Apply firm crepe bandage for up to 4 weeks
- Rest and limited joint movement
- Always send the specimen for histopathology
🔍 Prognosis
- Benign and non-cancerous
- High recurrence, especially with non-surgical management
- Surgical removal reduces recurrence risk but does not eliminate it completely
📘 High Yield points
- Ganglion cysts transilluminate, unlike solid masses
- Observation is first-line for asymptomatic cases
- Aspiration is useful but has a high recurrence rate
- Surgical excision is definitive, especially for recurrent or symptomatic cysts
- Mucous cysts over DIP joints are linked with osteoarthritis
- Always assess joint mobility and nerve compression symptoms, especially with large cysts
