A ganglion foot cyst is a swollen pocket of tissue made up of a thick, gel-like fluid that usually develops on the top of the foot. It may look similar to a small tumor, but it is not cancerous and is often the result of a strain or injury to the foot. Although some cysts grow slowly over time, others can develop suddenly.
One of the most common causes of a foot ganglion cyst is an injury to the foot, such as falling and landing from an extended height or even tripping and landing awkwardly. The condition can also be caused by repeated movements over a long period of time, such as constant standing or walking. Arthritis can also cause excess fluid to build up between the joints, ultimately causing the fluid to form a cyst in the foot.
The symptoms of a ganglion foot cyst can vary depending on the individual. The cyst is typically circular with a firm texture that is slightly pliable when pressed. Ganglion cysts usually don't cause pain unless they press on nerves in the foot, which can make the area feel tender or numb.
A doctor will usually diagnose a ganglion foot cyst by physically examining its appearance and gently pushing it with your fingers to make sure it contains fluid and is not a hardened mass indicative of another condition. He or she may use a needle to remove a sample of the fluid from the cyst and examine it to make sure it is a thick gel and not blood or pus. In rare cases, the cyst may be contained under the skin and not really penetrate, so a doctor may have to do X-rays or magnetic resonance imaging (MRI) to diagnose it.
Ganglion cysts often go away on their own without any further treatment, but if the cyst is painful, a doctor may insert a syringe directly into it and remove any excess fluid to relieve pressure. If a person continues to have recurring cysts, they can be surgically removed using a procedure known as a ganglionectomy. During a ganglionectomy, a surgeon makes an incision near the cyst and cuts it out of the skin. Even with surgery, a ganglion cyst may come back in the future and require additional treatment.
If the cysts occur due to accidents or arthritis, they cannot be prevented and will usually keep coming back. A person who is prone to ganglion cysts due to repeated foot movements can help reduce the likelihood of them coming back by wearing supportive, close-fitting shoes. If shoes don't fit properly, your feet can move around too often in them, causing friction that can contribute to cyst formation.