A ganglion is a so-called synovial cyst also known as Gideon’s disease or a bible bump, the reason for the latter being that years ago a ganglion was “treated” by hitting it hard with a heavy book such as a bible. It is a fluid-filled swelling on the hand, which is attached to a tendon sheath or joint via a long, thin tube-like stalk and is clothed in synovial membrane. These elastic-feeling lumps on the skin can reach a few centimetres in size. The fluid inside the cyst is synovial fluid, which has accumulated and cannot flow back to the joint through the narrow stalk the cyst has formed with the joint. Therefore, ganglions tend to grow continuously.
Ganglions on the hand, especially on the back of the hand at the wrist joint, are common. The layman often supposes the cause is excessive stress leading to weakening of the joint capsule. As a rule, however, it is a hereditary weakness of the capsular ligament, which often appears in young women during puberty.
Occasionally there is a type of ganglion that results from trauma after a tear to the capsule or tendon sheath. Here it is mostly men that are affected.
Ganglions are not always visible in that some do not bulge upwards through the skin, but swell inwards. Here, especially, the diagnosis must be carried out using ultrasound and CRT scans. In general though, it is also important to distinguish harmless ganglions from tumours or diseases of the hand.
In some cases the ganglion will reduce on its own accord. Therefore, the treatment will simply be a case of wait-and-see if the symptoms are minimal and the hand is looked after. Drawing of the synovial fluid from the cyst does not usually promise much success because the cause of the ganglion formation (tube-like stalk) has not been eliminated, so the fluid can quickly begin to flow again.
The most effective therapy is surgical removal of the ganglion, but even here, in one fifth of cases, a ganglion will develop again. A further treatment method is to use arthroscopy to extend the cyst’s stalk and to remove any enlarged synovial membrane so that fluid will be able to flow back into the joint thus the cyst reduces or completely regresses.