Ganglion

What is a ganglion cyst?

Wrist ganglion cyst

© GEMalone, CC BY 3.0, via Wikimedia Commons

A ganglion cyst is a small swelling that contains a thick jelly-like material. It looks and feels like a smooth lump under the skin. It is not fully understood how it occurs but most experts think that they occur due to multiple micro-traumas to the area of the body.

A ganglion is usually attached to a joint or tendon, and the fluid inside is a thicker version of the fluid which 'lubricates' the joint and tendon sheaths (synovial fluid).

Where are ganglion cysts found?

• Back of the wrist. The most common site for a ganglion to be found is on the back of the wrist. 7 out of 10 ganglion cysts are found here.

• Front of the wrist (the same side as the palm). It can also occur on the other side of the wrist. 2 out of 10 ganglion cysts are found here.

• Top of foot, ankle, top parts of the fingers. 1 out of 10 ganglion cysts are found here.

Other sites of the body are affected less commonly.

• Swelling. The main symptom is a lump, which is usually very smooth and round.

• Size. Their size can vary from being very small (pea-sized) to being larger (plum-sized).

• Painful. They can sometimes be painful or tender, particularly if they lie next to a nerve.

• Never spread. They never spread to other areas of the body.

Usually when a ganglion cyst is present it is there all the time but sometimes they come and go. 5 out of 10 ganglion cysts disappear completely over time without any treatment.

Your doctor will usually be able to tell if the lump is a ganglion just by examining it. Very occasionally, if the diagnosis is not clear, a scan such as an ultrasound scan או MRI scan may be needed.

If a ganglion cyst does not cause symptoms it can be best just to leave it alone. However, many people prefer to get rid of them.

Many people have heard of the traditional cure, which is to smash them with a heavy book (tradition holds it to be the family bible). This bursts the cyst under the skin. The fluid is then absorbed into the bloodstream. In some people this works well, but there is a high chance of it coming back (recurring), as the walls of the cyst can reform. It is not usually recommended as there is a risk of injury to the area around the ganglion cyst.

Medical treatment is not always available on the NHS.

In some cases it is possible to suck out (aspirate) the fluid with a needle and syringe. If the jelly-like fluid is very thick this may not work. Also, if it does work, there is a chance that the cyst will recur, as the wall of the cyst is not removed, and the fluid may form again to refill the ganglion. However, in some people it cures the problem. As it is quite easy for a doctor (usually an orthopaedic surgeon) to do, this is often attempted first.

Surgical removal of the ganglion cyst is the most successful cure. This is a relatively minor operation. This is the treatment that is most likely to be permanent but still around 3 cases in 20 will come back.