Exams and Tests

A ganglion can usually be diagnosed by its appearance and location and by feeling the bump. Your doctor will also ask questions about your medical history and do a physical exam. In some cases, an X-ray or other imaging test may be needed.

Your doctor may shine a light alongside the bump. If the bump is a ganglion, the light usually shines through it (transillumination). Your doctor may ask you how long you have had the ganglion and whether it changes in size or is painful, and he or she may apply pressure to see if it is tender.

An X-ray may be used to:

• Determine changes in bone near the ganglion. Sometimes ganglions can damage wrist or finger bones and ligaments.
• Check for other conditions, such as a bone spur (a small, bony growth that forms along a joint), a bone tumor, or osteoarthritis.

In rare cases, an ultrasound or magnetic resonance imaging (MRI) is used to evaluate unusual ganglions and ensure that a tumor is not present.

A ganglion can also be diagnosed by draining the fluid (aspiration) and evaluating it. The ganglion may temporarily go away after the fluid is removed, but it is likely to come back.