A ganglion cyst is a fluid-filled swelling of the lining of a joint or tendon. Ganglions can form on any part of the foot. But they most often appear on the ankle or top of the foot. They tend to change in size. They may even go away and return later.

Experts don't know what causes ganglions. They may be linked to repeated irritation that weakens the tissues around a joint or tendon, or to an injury.

Ganglion cysts often form with no symptoms. A noticeable lump is seen. If ganglions swell, they may put pressure on the nerves and the overlying skin. This can cause tingling, burning, numbness, or pain. Sometimes you feel a dull ache which may mean the cyst is pressing against a structure, such as a tendon or nerve. Their size can change with different activities.

Ganglion cysts are sometimes mistaken for tumors. So it's important to have a complete exam done. Tests may be done to confirm the diagnosis.

Your doctor will ask you questions. These include how long you've had the ganglion. And what kind of symptoms you're feeling. They may ask if it's changed in size or if its size varies based on your activities.

Your doctor may do a transillumination exam. This is done by shining a light through the swelling. You can often see through a ganglion. But not through a tumor. When your foot is pressed (palpated), a ganglion feels spongy and the fluid moves from side to side.

If a bone spur or arthritis is suspected, X-rays may be needed. Fluid removal (needle aspiration) may be done so the fluid can be tested. Removing some of the fluid may also help to decrease pain. To confirm a ganglion, an ultrasound or MRI scan may be done.

Nonsurgical methods are usually tried first, and may be helpful in relieving your symptoms. If a ganglion continues to bother you, your doctor may remove fluid from the ganglion (aspiration). Surgery to remove the ganglion may also be done.

• Pads placed around the ganglion can ease pressure and friction.
• Fluid removal may also ease symptoms. This is done with a needle. A steroid may be injected at the same time. But ganglions may come back.
• Limiting movements or activities that increase pain may bring relief.
• Icing the ganglion for 15 to 20 minutes may relieve inflammation and pain for a short time.

Surgery may be needed if a ganglion is causing ongoing or severe pain. The entire ganglion wall is removed during the procedure. Some nearby tissue may also be removed. Ganglions sometimes come back after surgery.

You may feel pain, swelling, numbness, or tingling for several weeks following surgery. You should be able to walk soon afterward. But your foot may need to be wrapped or in a cast, boot, or hard shoe. See your doctor if you notice any future problems. Surgery is often successful. But there is a chance that the ganglion will come back.