Ganglion cysts are a common condition that can develop on the top or bottom of the foot. They are not harmful or cancerous, although they may cause discomfort. Ganglion cysts that are painful or interfere with walking are treated first with non-surgical methods, or surgical removal, if needed.
The bones in your feet are connected with ligaments. Ligaments are firm tissues that connect bones together. They provide support and enable you to move your foot. The ligaments are lined with a synovial membrane. The synovial membrane secretes a thick liquid called synovial fluid that acts as a lubricant and cushion between the foot joints.
Ganglion cysts arise from the fluid filled areas on the ligaments or between the bones. The cyst is a sac-like structure filled with fluid. The fluid is harmless but can become thicker over time, making the cyst feel firm and spongy. A ganglion cyst can grow large, but it will not spread to other parts of your body.
The exact cause of ganglion cysts is unknown. They tend to develop after an injury or from too much stress on the foot.
A ganglion cyst appears as a lump underneath the skin. It is common for ganglion cysts to grow large, over one inch in diameter. They may come and go or disappear on their own.
Ganglion cysts may be painless, but they can cause tingling, burning, numbness, aching, or pain if they are on or near a nerve. The cyst may interfere with wearing shoes or walking.
You should have your doctor evaluate a suspected ganglion cyst, but it is not a medical emergency. A ganglion cyst can be diagnosed by reviewing your medical history, discussing your symptoms, and conducting an examination.
Sometimes doctors use needle aspiration to confirm the diagnosis of a ganglion cyst. This simple procedure involves numbing the area and then using a syringe and needle to draw fluid from the cyst. The fluid is examined to confirm the diagnosis and rule out any other condition.
In some cases, imaging tests, such as ultrasound or magnetic resonance imaging (MRI) scans, are used to gather more information about the cyst and surrounding structures. Imaging tests are helpful to determine if a growth is fluid-filled or solid. The images may also show if an artery or blood vessel is causing the bump.
Some ganglion cysts may go away without treatment. Your doctor may monitor your cyst if it does not bother you or interfere with walking. You should wear shoes that do not irritate your cyst. Shoe pads may reduce pressure on a cyst.
Needle aspiration is also used as a treatment for ganglion cysts. After the fluid is removed, the site is injected with steroid medication. Needle aspiration is a fairly successful treatment, although some people may need to have repeated procedures.
Outpatient surgery is recommended if the ganglion cyst is painful, causes numbness or tingling, or interferes with walking or movement. After the area is numbed, the cyst is surgically removed.
Recovery from surgery differs from person to person, depending on the size of the cyst and the extent of the surgery. Your doctor will let you know what to expect. Some people may need to participate in physical therapy to mobilize and strengthen the foot. The majority of cysts do not return; however, in a few cases, cysts return following needle aspiration or surgical treatment.