Causes The cause of these dilatations on the tendon-sheaths is either some irregular growth of the SYNOVIAL MEMBRANE which lines them and secretes the ?uid that lubricates their movements, or the forcing-out of a small pouch of this membrane through the sheath in consequence of a strain. In either case a bag-like swelling forms, whose connection with the synovial sheath becomes cut o?, so that synovial ?uid collects in it and distends it more and more.
Symptoms A soft, elastic, movable swelling forms, most often on the back of the wrist. It is usually small and gives no problems. Sometimes weakness and discomfort may develop. A ganglion which forms in connection with the ?exor tendons in front of the wrist sometimes attains a large size, and extends down to form another swelling in the palm of the hand.
Treatment Sudden pressure with the thumbs may often burst a ganglion and disperse its contents beneath the skin. If this fails, surgical excision is necessary but, as the ganglion may disappear spontaneously, there should be no rush to remove it unless it is causing inconvenience or pain.... Medical Dictionary