Ganglion: Symptoms & Signs

Medically Reviewed on 9/10/2019

Ganglion is a term that refers to a cyst (sac-like swelling) that forms from the tissue that lines a joint or tendon (known as synovium). The plural form of ganglion is ganglia. Ganglia can develop anywhere in the body, but they are most common around the wrist and ankle joints.

Signs and symptoms of a ganglion include a soft lump in the affected area. A large ganglion may cause a sensation of tightness, but they are not typically painful and usually do not show signs of inflammation. A ganglion in the back of the knee is known as a Baker cyst.

Causes of ganglion

The cause of a ganglion cyst is not always known, but they may sometimes develop after trauma to an area.

Other ganglion symptoms and signs

Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.