A ganglion cyst is a small, fluid-filled sac which commonly develops in the hand or the wrist. These cysts are similar to small water balloons, except that the fluid inside the cyst is thick and gelatinous, and very similar to honey in its consistency. Ganglion cysts are typically found near joints and tendons, especially the wrists and fingers. When a ganglion cyst occurs next to a fingernail, it is called a mucous cyst.
What causes ganglion cysts?
Ganglion cysts typically arise from a nearby joint or tendon. The lining of the joint or tendon can have an area of weakness, allowing an extra amount of fluid to collect. This extra fluid pushes out the lining of the tendon or joint, creating the cyst. The cyst is usually attached to the joint or tendon by a small stalk and motion can pump fluid into the stalk, enlarging the cyst. Ganglion cysts occur spontaneously with no known cause. They can occasionally occur after a minor injury such as a sprain or a penetrating injury such as a splinter.
Ganglion cysts are benign and do not require any treatment. They can increase or decrease in size, and may disappear completely over several weeks or months. They can also persist indefinitely.
Occasionally, ganglion cysts can become painful or increase in size to the point that they interfere with activities. Under these circumstances, there are two options for treatment.
Removing cyst fluid
The first option is to drain the cyst by removing the fluid, which is called aspiration. The skin overlying the cyst is anesthetized and the cyst is aspirated with a needle and the fluid evacuated. Because the fluid is extremely thick, it is sometimes not possible to completely evacuate all of the fluid. In addition, the lining of the cyst, although collapsed, is still present and the cyst can re-accumulate additional fluid. Only 10-15 percent of individuals have relief of their symptoms following a single attempt at drainage. If the cyst recurs and three or four additional aspirations are performed, the success rate improves to approximately 30 percent. Despite the low success rate, aspiration is preferred by many patients due to its simplicity and very low risks. Complications following aspirations are extremely rare. The most common complication which occurs is infection which is usually treated with antibiotics.
The remaining option for treatment is surgical excision of the cyst. Surgery includes an exploration of the surrounding tissues in order to remove the source of the cyst. This requires a deep surgical dissection to the adjacent joint or tendon. Surgery is performed as an outpatient. The success rate following surgery is much higher than aspiration. Ninety percent of individuals will experience relief in their symptoms with no recurrence of the cyst. Even with complete excision of the cyst, approximately five to ten percent of individuals will experience a recurrence within several years of surgery. In addition, there are are risks associated with surgery such as infection and neurovascular damage. Surgery leaves a scar which can be cosmetically noticeable. Surgery can also result in joint stiffness which may take several weeks to resolve. These risks are extremely low and can be discussed in detail with your physician.
If the ganglion is not causing any symptoms, no treatment is necessary and patients can resume normal activities. After aspiration most patients are able to immediately resume all activities. Following surgery, most patients are able to resume their normal activities once recovery is complete. This usually takes three to six weeks, depending upon the particular surgery involved.