Often, patients will see a doctor when they notice a painless lump in the wrist, hand, or finger. This lump can come and go at regular intervals. Such a mass is filled with synovial fluid, which is normally found inside a joint; an abnormality in the ligament system of this joint allows this fluid to escape and form a mass under the skin. It is more frequently associated with repetitive movements.
The first treatment is observation. In a number of cases, the cyst can disappear spontaneously for good. Otherwise, a puncture (aspiration) can be performed to remove the fluid from the cyst, hoping that this will be enough. Finally, a surgical approach involving the removal of the cyst and the stalk that attaches it to the joint often yields the best results.