What is a ganglion cyst?
A ganglion cyst is a round, fluid-filled lump that most commonly develops on or around a joint or tendon sheath. They are the most common soft tissue lump on the hand and wrist, though they can also occur on the foot, ankle, and knee.
The cyst contains a thick, jelly-like fluid similar to the synovial fluid that lubricates joints and tendons. They are entirely benign — they are not a form of cancer and do not become cancerous. However, they can cause discomfort, weakness, or cosmetic concern, particularly when they occur on the back of the wrist.
What causes a ganglion cyst?
The exact cause of ganglion cysts is not fully understood. They are thought to arise from a weakness or defect in the outer layer of a joint capsule or tendon sheath, through which synovial fluid leaks and accumulates, forming the cyst.
They are more common in:
- Women (ganglion cysts are approximately three times more common in women)
- People aged 15–40
- Those who have had a previous wrist injury
- People who perform repetitive hand and wrist movements
Symptoms
The most common presentation is a visible lump — typically firm, smooth, and fixed in position. Other symptoms can include:
- Pain or tenderness, particularly with certain wrist movements or after prolonged use
- Weakness of grip
- Tingling or numbness if the cyst presses on a nearby nerve
- Cosmetic concern, particularly for cysts on the back of the wrist
Some ganglion cysts are occult — too small to be seen but tender on examination. Ultrasound is particularly useful for identifying these hidden cysts.
How is a ganglion cyst diagnosed?
Ganglion cysts can often be diagnosed on clinical examination. They transilluminate — meaning they allow light to pass through them — which helps distinguish them from solid lumps. Ultrasound imaging confirms the diagnosis, accurately assesses the size and extent of the cyst, and identifies its relationship to surrounding structures.
At Alton Pain Clinic, ultrasound is used both for diagnosis and to guide treatment.
How to get rid of a ganglion cyst?
Watchful waiting
Many ganglion cysts resolve spontaneously without treatment — studies suggest around 50% will disappear on their own within two years. If the cyst is not causing significant symptoms, watchful waiting is a reasonable first approach.
Aspiration (needle drainage)
Aspiration involves drawing the fluid out of the cyst with a needle. Under ultrasound guidance, a fine needle is inserted into the cyst and the jelly-like contents aspirated. This is minimally invasive, quick, and can be performed in the outpatient clinic.
The recurrence rate after aspiration is higher than with surgery — around 50–80% of aspirated cysts recur within 12 months. However, some patients find that repeated aspiration adequately manages the cyst without the need for surgery, and recurrences can be treated again.
Ultrasound-Guided Corticosteroid Injection
Sometimes, after draining the fluid, a steroid is injected into the cyst cavity to reduce inflammation and decrease the likelihood of the ganglion returning. The corticosteroid can help reduce swelling and may provide longer-term relief.
This article is intended for informational purposes only and should not replace professional medical advice. If you are experiencing persistent symptoms, please consult a qualified clinician.
Frequently Asked Questions
Is a ganglion cyst serious?
No. Ganglion cysts are entirely benign. They do not become cancerous and are not associated with any serious underlying condition. Treatment is indicated if they cause pain, weakness, numbness, or cosmetic concern, but many people choose to leave an asymptomatic cyst alone.
Does aspiration hurt?
Aspiration is generally well tolerated. Local anaesthetic cream or a small injection of local anaesthetic can be used to numb the area beforehand. Most patients experience minimal discomfort during the procedure. The wrist may be a little sore for a day or two afterwards.
Will a ganglion cyst go away without treatment?
Yes — around 50% of ganglion cysts resolve spontaneously within one to two years. If the cyst is not causing you problems, it is reasonable to wait and see. If it is causing symptoms or you would like it removed, aspiration or surgery are effective options.