A ganglion cyst is a fluid-filled swelling that usually develops near a joint or tendon. The cyst can range from the size of a pea to the size of a golf ball. It most commonly occurs around the wrist and the dorsum of the foot (joint capsule origin), or along the flexor aspect of the fingers and on the peroneal tendons (tendon sheath origin). Although ganglia are among the commonest of surgical lumps, their origin is uncertain. They may represent a benign myxoma of joint capsule or tendon sheath, a hamartoma or a myxomatous degeneration due to trauma. They are thin – walled cysts with a synovial lining, and contain clear colourless material with the consistency of KY Jelly.
The lumps associated with ganglion cysts can be characterized by:
- Location: Ganglion cysts most commonly develop along the tendons or joints of your wrists or hands. The next most common locations are the ankles and feet. These cysts can occur near other joints as well.
- Shape and size: Ganglion cysts are round or oval and usually measure less than an inch (2.5 centimeters) in diameter. Some are so small that they can’t be felt. The size of a cyst can fluctuate, often getting larger when you use that joint for repetitive motions.
- Pain: Ganglion cysts usually are painless. But if a cyst presses on a nerve — even if the cyst is too small to form a noticeable lump — it can cause pain, tingling, numbness or muscle weakness
Factors that may increase your risk of ganglion cysts include:
- Your sex and age: Ganglion cysts can develop in anyone, but they most commonly occur in women between the ages of 20 and 40.
- Osteoarthritis: People who have wear-and-tear arthritis in the finger joints closest to their fingernails are at higher risk of developing ganglion cysts near those joints.
- Joint or tendon injury: Joints or tendons that have been injured in the past are more likely to develop ganglion cysts.
If you have a bump, you should see your doctor, even if you don’t have symptoms that bother you. A physical exam is often all that is needed to diagnose a ganglion cyst.
- Your doctor may get further confirmation by using a syringe to draw out some of the fluid in the cyst (needle aspiration) or by using ultrasound. An ultrasound picture is made as sound waves bounce off of different tissues. It can determine whether the bump is fluid-filled (cystic) or if it is solid. Ultrasound can also detect whether there is an artery or blood vessel causing the lump.
- Your doctor may send you to a hand surgeon if the bump is large or solid or involves a blood vessel (artery).
- MRI is used to see the wrist and is very useful for ganglions. One drawback to this diagnostic method is the cost of the procedure.
Ganglion cysts are often painless, requiring no treatment. Your doctor may suggest a watch-and-wait approach. If the cyst is causing pain or interfering with joint movement, your doctor may recommend:
- Immobilization: Because activity can cause the ganglion cyst to get larger, it may help to temporarily immobilize the area with a brace or splint. As the cyst shrinks, it may release the pressure on your nerves, relieving pain. Avoid long-term use of a brace or splint, which can cause the nearby muscles to weaken.
- Aspiration: In this procedure, your doctor uses a needle to drain the fluid from the cyst. The cyst may recur.
- Surgery: This may be an option if other approaches haven’t worked. During this procedure, the doctor removes the cyst and the stalk that attaches it to the joint or tendon. Rarely, the surgery can injure the surrounding nerves, blood vessels or tendons. And the cyst can recur, even after surgery.