What is a ganglion cyst?
A ganglion cyst is a fluid-filled swelling that develops near a joint or a tendon. The cyst can range from the size of a pea to the size of a golf ball.
Ganglion cysts look and feel like a smooth, soft lump under the skin. They are made up of a thick, jelly-like fluid, called synovial fluid, which surrounds joints and tendons to lubricate and cushion them during movement.
Ganglions can occur alongside any joint in the body, but are most common on the wrist (particularly the back of the wrist), hand and fingers. It can happen in the foot as well.
Ganglions are generally harmless, but they can sometimes be painful, especially if they are next to a nerve.
It is not clear why ganglions form, but they may be related to ageing or injury to the joint or tendon. They occur when the synovial fluid that surrounds a joint or tendon leaks out and collects beneath the skin.
Treatment is usually only recommended if the cyst causes pain or affects the range of movement in a joint.
The two main treatment options for a ganglion cyst are:
- draining fluid out of the cyst with a needle and syringe (the medical term for this is aspiration)
- cutting the cyst out by way of surgery
Aspiration is carried out under local anaesthetic (where the area is numbed), usually in the outpatient orthopaedic clinic.
The skin over the lump is cleaned and numbed with a small local anaesthetic injection. Your doctor will remove as much of the contents of the ganglion as possible with a needle and syringe.
After the procedure, a plaster is placed over the small hole in your skin, which can be removed about six hours after the procedure.
Aspiration is a simple and painless procedure and you will be able to resume your normal activities straight afterwards. It is often the first treatment option offered for ganglion cysts as it is less invasive than surgery.
However, small percentage of all ganglion cysts treated using aspiration will return at some point. If a cyst does return, surgery may be necessary.
There are two ways that surgery can be used to remove a ganglion cyst:
- open surgery – where the surgeon makes a small cut, over the site of the affected joint or tendon
- arthroscopic surgery – a type of keyhole surgery where smaller incisions are made and a tiny camera, called an arthroscope is used by the surgeon to look inside the joint. Using the arthroscope as a guide, they then pass instruments through the incision to remove the cyst
Both techniques can be performed under either local or general anaesthetic.
Having a local anaesthetic means that you will be awake but will not feel any pain. Having a general anaesthetic means that you will be asleep during the operation.
Open or keyhole surgery?
Both techniques are equally effective in removing the cyst and reducing the risk of it returning.
After the operation
The surgeon will stitch up the wound and a bandage will be placed over the area. This helps keep the area clean, reducing the risk of infection, and safe from any accidental bumps. The wound is not usually painful.
It is likely that you will experience some bruising in the area after your operation, but this should fade quickly.
How much time you need to take off work after surgery to remove a ganglion cyst will largely depend on your job.
Having a ganglion cyst removed is a minor procedure, so complications are rare and seldom serious.