A ganglion cyst is a fluid filled sac that can occur anywhere on the body. The fluid is normal fluid from a joint or a tendon sheath that has escaped to an abnormal area. In the hand and wrist, there are a few common areas for cysts to develop. If the cyst is symptomatic, aspiration is one treatment option. The skin is numbed with a local anesthetic agent, then a large-bore needle is inserted into the cyst to drain the fluid. Is it uncommon to be able to drain all the fluid, and therefore patients are encouraged to massage the area to help any residual fluid make its way out of the sac. Recurrence rates after needle aspiration are high: 50-90% depending on the location. Ultrasound maybe used to confirm that the bump in question is a cyst, and the ultrasound may be used to help guide the position of the needle to optimize the aspiration. If the ultrasound shows the bump to be something other than fluid (a solid tumor) attempted aspiration is not recommended. The bump may need to be further evaluated with an MRI, or surgical excision may be recommended.