A ganglion cyst is a benign soft tissue tumor that develops along a tendon sheath or joint. Inside the cyst is a thick, gelatinous liquid. Depending on the size, it may feel firm or spongy. The cyst can increase or decrease in size with movement. They most commonly occur on the hands, but can also occur on the ankle or top of the foot. When the cyst is larger, it can cause pain or irritation by rubbing on the shoe or may irritate the nerve underneath.
The cause of ganglion cysts is not known. One theory suggests that trauma causes the tissue of the joint to break down, forming small cysts that then join into a larger, more obvious mass. The most likely theory involves a flaw in the joint capsule or tendon sheath that allows the joint tissue to bulge out.
What are the treatment options?
If the cyst causes no pain and does not interfere with shoe gear, you may choose to do nothing. This is certainly an acceptable course of action, but if the cyst continues to enlarge or become painful, some sort of intervention is advised.