What is a Ganglion Cyst?
A ganglion cyst is a fluid-filled sac that commonly forms in the wrist. The majority of ganglion cysts are benign (not cancerous). They are usually caused by a stretching of the joint capsule under pressure from a weakness in the ligament wall, creating a sac. We call it the “bubble gum effect” – when you blow a bubble, pressure forces air into the stretched out gum and it expands until it pops. Picture bones as your lips, and the ligament (holding two bones together) as the bubble gum. When fluid builds up in the wrist, it can stretch out the ligament in a specific spot and create the cyst. The cysts can be large or small, and painful particularly with movement of the wrist. Sometimes they can go away on their own. In the old days, people would take books or bibles and hit the cyst hard in the hopes of popping it.
Diagnosis is typically made by a qualified physician performing a history and physical exam. Sometimes a doctor will shine a light (transillumination) on the cyst. The doctor tries to determine whether or not it is fluid filled or more like a solid mass. Sometimes ganglion cysts are hard to detect on the exam, and an MRI is necessary. These cysts that are not visibly seen but present are known as occult cysts. X-rays are less useful but can show the shadow of the cyst. Ultrasound can be helpful to determine the location, size, and other characteristics of the cyst.
Although ganglion cysts can occur in several places, these locations are most common:
Dorsal: Backside of the wristVolar: Palm side wrist (commonly near radial artery)
What are the treatment options?
Since most ganglion cysts are benign, you can live with it as long as it does not bother you. Sometimes they can become painful with wrist range of motion. Resting the wrist with or without the aid of a splint may help. Aspiration (drawing fluid out of the cyst) is also an option. Most of the time the cyst may recur after the aspiration because once the sac seals itself up, it will fill up again with fluid. The fluid is very gelatinous. Sometimes it can be bloody. Aspiration for volar ganglion cysts should be done only with extreme caution or not at all because of their proximity to the radial artery.
Surgery for treatment of Ganglion Cysts
Surgery or excision of ganglion cysts is an outpatient procedure. It typically takes about 20 to 30 minutes. There are different techniques of excising a cyst. Most patients have them excised because they can cause pain, particularly with the range of motion. About 10-15 % of the time, the cyst can recur after excision. We typically go to the “root” of the cyst and take it out. This reduces the chance of recurrence. Not all physicians do that. Surgeons can also perform an arthroscopic excision of ganglion cysts. The arthroscopic procedure is technically more challenging, can take longer, and could have a higher recurrence rate.