Ganglion cysts are common fluid filled lumps that form next to joints or tendons. Although they often feel firm like a solid object, they are actually filled with the thick fluid that lubricates the associated joint or tendon. Ganglions are not really tumors and do not generally damage the surrounding tissues. Most of the problems associated with ganglions are related to the pressure they apply on their surroundings and the associated discomfort.
Although they can occur almost anywhere, certain locations in the upper extremity are extremely common. Around the back or palm side of the wrist, grape-sized cysts are common to see in children and young adults. On the palm side of the fingers, small, BB-sized cysts can sometimes form on the tunnel that covers the tendons that bend the fingers (the flexor tendon sheath). These are generally located at the end of the sheath where the finger attaches to the hand. A specific variety of ganglion cyst, sometimes referred to as a mucous or myxoid cyst, is commonly found around the tip joints of the fingers and thumb. These small cysts are almost always associated with underlying arthritis and are rare to see in people under the age of 40.
Outside of the cysts associated with arthritis or a specific tendonitis, the exact cause for most ganglion cysts is unknown. Anything that causes increased fluid production around a joint or tendon (such as over-activity) may result in formation of a cyst or enlargement of an existing cyst. Likewise, when activity is reduced, cyst size often decreases.
Treatment decisions are often based on the location, size and discomfort of a given cyst. Small cysts with minimal pain are often left alone. Bracing or splinting the affected area may temporarily decrease the size of the cyst and reduce pain. “Old school” methods of cyst treatment such as striking them with a heavy book are generally not recommended due to their potential for local injury and the high recurrence rate. Draining the cyst with a needle and syringe (aspiration) is sometimes used to give people quick relief from the pressure-related pain. Although relatively simple to perform, the recurrence rate is quite high, mostly because the shell of the cyst is still present and connected to the joint or tendon.
When a ganglion is causing significant discomfort and has not responded to simple measures, surgery is often considered. Most ganglion cysts can be removed in a safe, outpatient surgery that does not require general anesthesia. Although varying by location, most ganglions have a recurrence rate of 10-15% after surgery (85-90% permanent removal).