Ganglions are small sacs of tissue filled with a gel-like substance and found in synovial spaces. A synovial space has synovial fluid within it which lubricates a tendon or joint. Most ganglions are seen around joints, for example wrist and fingers. Ganglions around the fingernails are called mucous cysts and can deform the nail. They arise in the end joint of the fingers and are more common in women than men.
The exact cause of ganglions is not known but theory has it that a weak area in the capsule surrounding a space blows out, allowing fluid from the joint to leak and form a small bubble. Fluid continues to leak into the bubble and remains trapped and the ganglion increases in size. Ganglions are also found around tendons, commonly in the palm of the hand or base of the fingers and occasionally the wrist.
Ganglions are not cancerous and can be left alone if they are causing no discomfort. Pain in a ganglion is associated with tension in the wall of the ganglion, that is, stretching of the tissues and can usually be relieved by aspiration or sucking out the fluid. Ganglions often return and repeated aspiration is required.
If the ganglion remains painful or unsightly despite repeated aspirations, it can be surgically removed as a day procedure under local anaesthesia with sedation. Larger or more complex ganglions may need general anaesthesia. This surgery involves changing the nature of the leak from the synovial space so the ganglion doesn't form. A small scar will result over the area where the ganglion was. Even after surgery ganglions can return.
Complications of this surgery are rare. They can include wound infection or bleeding, hand stiffness, scar tenderness and, rarely, nerve injury.