A ganglion is a cystic swelling in continuity with a joint capsule or tendon sheath. It is a degenerative disorder  arising from the joint capsule. It is filled with clear, viscous fluid. Ganglia are common on the dorsum of the wrist.

They are often painless and resolve spontaneously Often, only reassurance of the patient is required. Wrist splints relieve the pain. Aspiration and injection are rarely effective. Surgical excision is best avoided as recurrence rate after surgery is quite high.