What it means
A ganglion cyst is a pocket of thick, clear, jelly-like fluid next to a joint or the sheath around a tendon. It often has a narrow stalk that connects it to the joint. The back of the wrist is the most common site. Ganglia also occur on the palm side of the wrist, in the fingers, and around the foot and knee. On ultrasound and MRI it looks like a smooth, fluid-filled sac, sometimes with several lobes.
When it matters
Ganglion cysts are benign, meaning they are not cancer. Ultrasound is often used to confirm that a lump is a cyst rather than a solid growth. Many cause no trouble, and some go away on their own. They matter if they hurt, limit movement or press on a nerve, causing numbness, tingling or weakness. Your doctor may suggest watching it, draining it with a needle or removing it. They can come back after draining or removal.
Questions to ask your doctor
- Is the cyst connected to a joint or to a tendon sheath?
- Is it pressing on a nerve or tendon?
- Is it fine to watch it, or is draining or removal worth discussing?
