Ganglion cyst

A ganglion cyst is a fluid-filled swelling that usually develops near a joint or tendon. The cyst can range from the size of a pea to the size of a golf ball.

Symptoms of a ganglion cyst

Ganglion cysts look and feel like a smooth lump under the skin.

They're made up of a thick fluid called synovial fluid. This surrounds joints and tendons to cushion them during movement.

Ganglions can happen near any joint in the body. But they are most common on the wrists, hands and fingers.

Ganglions are harmless, but can sometimes be painful. If they do not cause any pain or discomfort, they can be left alone and may disappear without treatment. This can take years.

It's not clear why ganglions form. They seem to happen when the synovial fluid that surrounds a joint or tendon leaks out and collects in a sac.

Treatment for a ganglion cyst

Treatment is usually recommended if the ganglion cyst causes pain or affects the movement in a joint.

The 2 main treatment options for a ganglion cyst are:

• draining fluid out of the cyst with a needle and syringe (aspiration)
• cutting the cyst out using surgery

Aspiration

Aspiration is usually carried out in the outpatient department of your local hospital or GP surgery.

Your GP will use a needle and syringe to remove as much of the fluid of the ganglion as possible.

The area is sometimes also injected with a dose of steroid medicine to help stop the ganglion from returning. There's no clear evidence this reduces the risk of it coming back.

After the procedure, a plaster is placed over the small hole in your skin. This can be removed after around 6 hours.

Aspiration is often the first treatment option offered for ganglion cysts as it's less invasive than surgery. It's simple and painless. You'll be able to go home straight after.

Around half of all ganglion cysts treated using aspiration return at some point. If a cyst does return, surgery may be necessary.

Surgery

There are 2 ways surgery can be used to remove a ganglion cyst.

Open surgery

The surgeon makes a medium-sized cut, usually about 5cm (2in) long, over the site of the affected joint or tendon.

Arthroscopic surgery

This is keyhole surgery where smaller cuts are made and a tiny camera (arthroscope) is used to look inside the joint. The surgeon will pass instruments through the cut to remove the cyst, using the arthroscope as a guide.

Both techniques are equally effective at removing the cyst and reducing the risk of it returning.

Keyhole surgery tends to cause less pain after the operation.

Both techniques can be performed under either:

• local anaesthetic - where you're awake but will not feel any pain, or
• general anaesthetic - where you're asleep during the operation

The choice depends on:

• where the ganglion is
• which anaesthetic you'd prefer
• what your surgeon thinks is best

After the operation

The surgeon will stitch up the wound and a bandage will be placed over the area.

This helps to:

• keep it clean
• reduce the risk of infection
• keep it safe from any accidental bumps

The wound is not usually painful, but you'll get painkillers to take if you feel any discomfort after the operation.

If the cyst was removed from your wrist or hand, you may need to wear a sling for the first few days. This helps keep your arm safe from any accidental knocks, and may help reduce swelling and discomfort. Move your fingers regularly to help keep the joints flexible.

Surgery to remove a ganglion cyst leaves a scar, which can sometimes be thick and red.

For some people, the skin around the scar remains numb after the operation. You'll usually have some bruising in the area after your operation. This should fade quickly.

There's also a small possibility of temporary stiffness, swelling or pain afterwards. This may be caused by a minor infection, which can be treated with antibiotics.

If you have lasting pain or stiffness, you may need further treatment with physiotherapy.

How much time you need to take off work after surgery depends on your job and where the ganglion is. If your job involves manual labour, you may need to take time off.

You can usually start driving again once it feels safe.

Complications

Having a ganglion cyst removed is a minor procedure. Complications are rare and usually not serious. A small number of people have permanent stiffness and pain after surgery.

If you have the operation under general anaesthetic, there's also a very small risk of complications to your heart and lungs. Pre-assessment tests before surgery should make sure your risks are as low as possible.

There's always a chance a ganglion cyst will come back after treatment. This is more likely if the ganglion is on certain areas of the wrist.