A ganglion cyst is a (typically benign) fluid-filled sac at the base of the wrist. Ganglion cysts are common, particularly among athletes between 15–40 years old. About 50 percent of the time, they will disappear on their own, but if they cause pain, excision is a preferred option.


  • Presence of a palpable, round sac under the skin, usually at the base of the thumb or on the backside of the wrist.
  • Intermittent pain and tenderness commonly accompany this condition.

A ganglion cyst forms when a wrist joint that is under pressure produces excess fluids. These fluids stretch out the ligament wall to form a cyst just under the skin.

If your ganglion cyst causes pain with wrist movement or contact with hard surfaces, you can have it aspirated or excised to relieve the pressure. First, though, a hand specialist will use transillumination (bright light) to determine that it is a fluid-filled cyst and not a solid mass. An MRI is sometimes used to delineate the structure of a more internal, occult cyst. Ultrasound can also help determine location, size, and other characteristics of the cyst.

Needle aspiration relieves the pressure, but in most cases, the sac refills with fluid. Excising the cyst at its root is generally the best permanent option. The hand surgeons at HSST are successful in the delicate extraction of ganglion cysts with low recurrence rates (under 10-15%). We may recommend open or arthroscopic surgery, depending on the location of the cyst and other factors.

Both of these outpatient procedures take 20–30 minutes and can be done with twilight anesthesia.