Plural ganglia.

1. A synovial fluid-filled cyst around the wrist, a ganglion, is common in childhood. The usual site is the dorsum of the wrisnear the radiocarpal joint; a common second site is over the volar radial aspect of the wrist. The disease is a defect in oneof the joint capsules, which allows herniation of the synovium through the defect. If the synovium is ruptured, the fluid maybe pumped into the soft tissues through the action of wrist motion; the fluid is subsequently walled off by reactive fibroustissue. In children, ganglia are benign and tend to disappear overtime. If a ganglion is sufficiently large, causes pain, orinterferes with normal tendon functioning, aspiration of the cyst is sometimes helpful. Surgical excision of the cystaccompanied by removal of the tract that extends into the joint is curative.

2. A mass of nerve tissue (grey matter) or a group of nerve cell bodies.

3. [anatomy] Also refers to specific groups within the brain or spinal cord (as basal ganglia).