A ganglionic cyst is a fluid filled sac arising from the lining of a tendon or joint. The most common cause is excess stress is one area due to shoe rub or faulty foot mechanics (abnormal joint or tendon function). Abnormal stress can weaken the lining of the tendon or joint capsule, resulting in an outpouching.
A ganglion appears as a soft, moveable, lump on the top of the foot. Although ganglion typically do not cause pain, repetitive irritation or pressure from shoes may result in tenderness. If the cyst forms above a nerve or is in an area which limits motion it may cause pain or limit function.
A physical exam is used to diagnose a ganglion cyst. Fluid can be aspirated (pulled from the cyst with a needle) and a clear, thick, jelly-like fluid will confirm the diagnosis. When the ganglion cysts are deep with the ankle or foot, an MRI may be needed to confirm diagnose.
Ganglionic cysts are not cancerous growths, they do not invade other structures and may not require treatment. If they are causing pain, irritation, discomfort or limit motion then conservative treatment should be initiated. Depending on the location, padding may help disperse pressure and decrease irritation, allowing the ganglion to shrink in size. It’s important to find shoes which do not excessively rub or place pressure on the cyst. Aspiration of the cyst fluid followed by a steroid injection may be successful. Surgical removal is only necessary when the cyst causes pain, irritation and discomfort or limits motion and activity and conservative therapy has failed.Ganglion