Ganglion cyst

Ganglion cysts are filled with synovial fluid, a jelly-like liquid that surrounds and protects your joints or tendons. A ganglion cyst occurs when synovial fluid leaks out and forms a liquid-filled sac under your skin.

Ganglion cysts most often affect the wrist but you can also get them on your fingers, ankles or feet. They can range in size from a pea to a plum and may shrink or swell over time.

Ganglion cysts can occasionally cause joint pain or stiffness but most don’t need treating. They’re non-cancerous and won’t spread or lead to long-term health problems.

Eventually, a ganglion cyst may go away by itself. However, successful treatments are available if a ganglion cyst is causing symptoms or if you’re bothered by the appearance.

The main symptom of a ganglion cyst is a smooth lump that appears under your skin. Ganglion cysts are most often found on:

• The back of your wrist
• The base of a finger
• The base of your thumb
• The end joint of a finger (near your fingernail)

The lump or swelling usually causes no trouble at all. However, you may have pain, tingling, numbness or stiffness in the nearby joint if the ganglion cyst is pressing on a nerve.

See your GP if you have a fluid-filled lump under your skin or have pain, numbness or tingling in your hand or wrist. 

Your GP will usually be able to diagnose a ganglion cyst by asking about your symptoms and medical history and by examining the swelling. When examining your swelling, they may press against it to check for discomfort or tenderness and shine a light on it to check whether it is fluid-filled or a solid mass.

They may refer you for an X-ray, ultrasound scan or an MRI scan to rule out other conditions such as osteoarthritis or, very rarely, a bone tumour.

It isn’t always clear why synovial fluid leaks out of your joint and forms a ganglion cyst. It is thought to occur when the tissue surrounding a joint or tendon bulges out of place. Ganglion cysts can occur for anyone at any age but are more common:

• If you have an old injury on the affected joint
• If you have osteoarthritis in your fingers
• In women aged 20–40

A ganglion cyst often goes away on its own, although this can take time. If it doesn’t, treatments to ease ganglion pain and stiffness include:

• Hand exercises
• Over-the-counter painkillers
• Wearing a wrist splint

If these don’t work, your doctor may recommend aspiration. This is a quick and painless procedure to drain fluid from the ganglion cyst using a thin needle and syringe. In some cases, an injection of steroid medication may also be given in this area to reduce the risk of the ganglion cyst returning — however, there is no clear evidence that this is effective. After your procedure, a plaster will be placed over the site where the fluid was drained, which you can remove after six hours. 

Aspiration is usually an outpatient procedure and once complete, you can leave straight away. It is often recommended first, before any surgical options, as it is less invasive. However, half of ganglion cysts treated with aspiration return. If your ganglion cyst returns, your doctor may recommend surgery.

Surgery is used to cut out your ganglion cyst and is carried out under local or general anaesthetic. There are two types of surgery to remove a ganglion cyst: 

• Arthroscopic surgery — this is a type of keyhole surgery and uses small cuts through which a tiny camera (an arthroscope) is passed, which allows your surgeon to look inside your affected joint and then pass instruments through to cut out your ganglion cyst
• Open surgery — this involves your surgeon making a medium-sized (about 5cm long) cut over your affected joint or tendon to remove your cyst

Arthroscopic surgery usually causes less pain after surgery than open surgery. 

Your doctor will discuss your treatment options with you to find the most appropriate option.

After your ganglion cyst surgery, your surgeon will stitch up your wound and a bandage will be placed over it to help keep it clean, protect it from accidental knocks and scrapes, and reduce the risk of infection. The wound isn't usually painful but if you experience any discomfort, you may be given painkillers. 

If your ganglion cyst was removed from your hand or wrist, you may need to wear a sling for several days after your surgery to protect your hand or wrist from accidental knocks and help reduce discomfort and swelling. Make sure you move your fingers to prevent your joints from getting stiff.

After your surgery, there may be bruising around the surgical site but this usually fades quickly. You may also experience temporary pain, stiffness and/or swelling around the affected joint. In some cases, this is due to an infection, which can be treated with antibiotics. If your job involves manual work, you may need to take time off to recover fully.

You will be left with a scar, which in some cases, can be red and thick and/or remain numb. If you experience ongoing pain or stiffness, your doctor may recommend physiotherapy. Once your affected joint or tendon feels better and you feel safe to do so, you can return to driving. 

Ganglion cyst surgery is a minor procedure. Complications are therefore rare, and usually not serious. For a small number of people, permanent pain and stiffness after surgery can occur. 

Any surgery carried out under general anaesthetic comes with a small risk of heart and/or lung complications — pre-assessment tests before your surgery should reduce these risks to as low as possible.

Even after surgery, your ganglion cyst may return, especially if your ganglion cyst was on certain areas of your wrist. 

To relieve any pain due to a ganglion cyst, you can try over-the-counter painkillers. If your ganglion cyst is on your ankles or feet, you can try adjusting your shoes or how you fasten them. If your ganglion cyst is on your wrist, you can try wearing a wrist splint. 

Do not thump your cyst with a heavy object — this was an old home remedy that is not effective and can damage the surrounding tissues. 

Do not try to pop the ganglion cyst yourself with a needle — this will most likely not work and could cause an infection.