A ganglion foot cyst is a swollen pocket of tissue comprised of thick gel-like liquid that typically develops on the top of the foot. It may appear similar to a small tumor, but it is not cancerous and is often the result of foot strain or injury. Although some cysts grow slowly over time, others may develop suddenly.
One of the most common causes of a ganglion foot cyst is an injury to the foot, such as falling and landing on it from an extended height or even just stumbling and landing awkwardly. The condition can also be due to repeated movement over a long period of time, like constant standing or walking. Arthritis may also cause excess fluid to build up between joints and may ultimately cause the fluid to form a cyst on 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 do not usually cause pain unless they press down 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 pushing it lightly with his or her fingers to ensure it contains fluid and is not a hardened mass indicative of another condition. He or she may use a needle to draw out a sample of the cyst’s fluid and examine it to ensure it is a thick gel and not blood or pus. In rare cases, the cyst may be contained underneath the skin and not actually poke through, so a doctor may have to perform X-rays or magnetic resonance imaging (MRI) to diagnose it.
Ganglion cysts often subside on their own without any additional treatment, but if the cyst is painful, a doctor can insert a syringe directly into it and remove all the excess fluid to relieve the pressure. If a person continues to have recurring cysts, he or she can have them surgically removed using a procedure known as a ganglionectomy. During a ganglionectomy, a surgeon makes an incision near the cyst and cuts around it to remove it from the skin. Even with surgery, a ganglion cyst can return in the future and require additional treatment.
If the cysts occur due to accidents or arthritis, they cannot be prevented and will typically continue to recur. A person who is prone to ganglion cysts due to repeated foot movements can help reduce the likelihood of them returning by wearing supportive, properly fitting shoes. If shoes don’t fit correctly, the feet may move too often inside of them and cause friction that may contribute to cyst formation.