A ganglion is a soft tissue mass that most commonly occurs on the wrist in women between 25 and 45 years of age. They are also seen commonly on the foot. A ganglion is a firm, rubbery mass that occurs on the top of the foot. On the foot, the most common area of involvement is in front of the ankle or on the outside of the ankle. A common characteristic of a ganglion is that they will enlarge and then shrink is size. They generally occur without any apparent cause. Ganglions arise spontaneously from a weakness in the soft tissue covering of a joint or tendon sheath. Ballooning out of the tissue occurs and it fills with a thick mucoid fluid. In many instances, ganglions are not painful until they reach a size that causes irritation from shoe pressure. On occasion they will compress a nearby skin nerve and cause tingling into the top of the toes. Tapping on the ganglion will often result in this same tingling sensation into the toes. Other common masses on the foot are giant cell tumors, fibromas and lipomas.
The diagnosis is made by taking a thorough history of the clinical course of the condition. Physical exam will reveal a firm, rubbery mass that appears encapsulated and has a discreet boundary. They tend to be firmly adhered to the underlying deep tissues under the skin. A x-ray will reveal the shadow of the soft tissue swelling. On occasion there may be a small bone spur in the area of the ganglion. Spurring indicates a level of arthritis in the joint near the ganglion. A MRI or CT scan will clearly define the mass but is not necessary to make the diagnosis. If a ganglion were suspected within the deep structures of the foot a MRI would be useful to identify the size and extent of the mass.
Small ganglions that are not symptomatic or painful usually require no treatment. A non-surgical form of treatment is termed "needling". This involves numbing the area with a local anesthesia. Once the area is numb a large gauge needle is placed into the ganglion. Aspiration of ganglion fluid is attempted, however, because of the thickness of the fluid it is often difficult to draw the fluid out. The ganglion is then punctured with the needle several times. A steroid medication may then be placed into the mass and a snug bandage applied. This treatment has a 70% recurrence rate. The definitive treatment for a ganglion is surgical excision. (See surgical excision of a ganglion)