It is still unknown what causes ganglion cysts. It may be inherited or caused by arthritis or trauma. Ganglion cysts grow out of joints or the lining in tendons. They are located at the center of the back of the wrist or on the palm side of the hand near the base of the finger or thumb. Ganglion cysts generally look like a balloon on a stalk.
Ganglion cysts are most commonly found along joints and tendons in either the hand or wrist. It is possible for them to also form at the ankles and feet. Size fluctuates but the cysts tend to enlarge with repeated use of the joint. Pain, tingling, and numbness is uncommon, but can occur if the cyst presses on a nerve.
In an exam, physicians will apply pressure to the cyst to determine tenderness and levels of discomfort. X-rays and MRIs may also be used to identify possible arthritis or hidden cysts.
Ganglion cysts often require no treatment and will go away over time. If the cyst is painful or is prohibiting motion, drainage with a needle or steroid injections can be used. This method may also reduce recurrence. Due to close proximity to the radial artery, cysts on the palm side of the hand cannot be drained with a needle and may require surgical removal.