Summary

Ganglion cysts are the most common soft tissue tumour of the hand and wrist (60-70% of all masses). They are benign, mucin-filled pseudocysts (no epithelial lining) arising from joint capsules or tendon sheaths via a one-way valve mechanism. The classic presentation is a painless, firm lump that transilluminates brilliantly. Diagnosis is clinical. While 50% resolve spontaneously (especially in children), symptomatic cysts can be treated. Aspiration is simple but has a 50% recurrence rate. Surgical Excision is the gold standard but carries risks of stiffness and recurrence (10%) if the capsular stalk is not removed. [1,2,3]

Key Facts

• Most Common Site: Dorsal Wrist (60-70%) overlying the Scapholunate Ligament.
• Second Site: Volar Wrist (20%) overlying the Radial Artery or STT joint.
• Pathophysiology: Mucin-filled clefts (Hyaluronic acid) formed by myxoid degeneration of collagen. Not a true cyst.
• Bible Bump: Historically treated by hitting it with a heavy book (Bible) to rupture the sac. Not recommended!

Clinical Pearls

"Transillumination is Key": Put a pen torch right against the skin. A ganglion glows like a lantern full of clear jelly. A solid tumour (GCT, Lipoma) blocks the light.

"The Volar Trap": Volar ganglions often wrap around the Radial Artery. Often the artery is pushed superficially on top of the cyst. ALWAYS perform an Allen's Test before surgery to ensure Ulnar Artery potency.

"The Occult Ganglion": A common cause of dorsal wrist pain in young women with no lump. The small cyst is hidden deep in the capsule, irritating the Posterior Interosseous Nerve (PIN). MRI detects it.

               GANGLION CYST
                     ↓
        SYMPTOMATIC OR COSMETIC CONCERN?
        ┌────────────┴─────────────┐
       NO                         YES
        ↓                          ↓
   OBSERVATION                ASPIRATION
   (Reassure)               (Dorsal Only!)
  - 50% Resolve             - 50% Recurrence
        ↓                          ↓
                            RECURRENCE?
                                   ↓
                           SURGICAL EXCISION
                           (Open or Arthroscopic)
                           - 10% Recurrence

Note: Aspiration of Volar Ganglions is dangerous (Radial Artery injury). Generally avoided.

1. Aspiration

• Technique: Local anaesthetic. Large bore needle (18G) required to draw thick jelly.
• Steroids?: controversial. May reduce recurrence slightly but risks skin depigmentation.
• Pros: Quick, office based.
• Cons: High recurrence (Valves remains).
• Indication: Dorsal cysts, first presentation.

2. Surgical Excision (Open)

• Technique:
  1. Incision over cyst (Transverse).
  2. Protects sensory nerves (SBRN/LABCN).
  3. Dissect cyst down to joint capsule.
  4. Excise the Stalk: A 5mm cuff of capsule must be removed to destroy the valve.
  5. Cauterize base.
• Recurrence: 5-10%.

3. Arthroscopic Excision

• Indication: Dorsal cysts.
• Technique: Resecting the stalk from inside the joint.
• Pros: Smaller scar. Evaluation of SL ligament.
• Cons: Technically demanding.

Head et al. (2015) Meta-Analysis

• Compared Surgical Excision vs Aspiration.
• Result: Surgery has significantly lower recurrence (Odds Ratio 0.14).
• Conclusion: Surgery is the definitive treatment, but aspiration is a reasonable first line for dorsal cysts due to low morbidity.

Pediatric Ganglions (Wang et al.)

• Observation is the gold standard. Spontaneous resolution rate is 79% within 1 year. Surgery has high recurrence in kids.

What is it?

It is a balloon of joint fluid leaking out of your wrist. The fluid gets trapped and thickens into jelly. It is perfectly harmless (benign).

Why do I have it?

There is a tiny weakness in the joint lining. It acts like a one-way valve - letting fluid out, but not back in.

Will it go away?

Often yes! 50% disappear on their own if you leave them alone for a year or two.

Can you drain it?

Yes, we can use a needle to suck the jelly out (Aspiration). It goes flat instantly. But because we haven't removed the "valve", it typically refills in about half of the cases.

What does surgery involve?

We make a cut, find the balloon, and trace it down to its root. We remove the root to stop it refilling. It leaves a scar and your wrist might be stiff for a few weeks. Discomfort from the scar can last longer than the cyst did!

Q1: What is the specific origin of dorsal wrist ganglia? A: The Scapholunate Ligament Interosseous Ligament (SLIL) and the dorsal capsule overlying it.

Q2: Why is the Allen's Test important for volar ganglia? A: Volar ganglia are intimately related to the Radial Artery (often displacing it). If the radial artery is injured during surgery, you must know if the Ulnar Artery is patent and can supply the hand (Palmar Arch integrity). If the Allen's test is abnormal (poor ulnar flow), surgery is high risk.

Q3: Differentiate a Ganglion from a Synovial Cyst (RA). A: A Ganglion is a pseudocyst with no synovial lining (fibrous wall). A Synovial Cyst (in RA) is lined by true synovium and is part of the inflammatory disease process.

(End of Topic)