Ganglion cysts are swellings of fluid on top of foot joints such as the big toe joint, the top of the foot and the ankle. A cyst by definition is a sac filled with fluid and it can feel hard or soft. Ganglionic cysts of the foot, wrists or hands are usually not dangerous and they usually occur between the ages of 20-40 years of age.
Ganglionic cysts can be though of as a protrusion of fluid from a joint that is still surrounded by a sac of membranous tissue. Think of this like squeezing a water balloon with your hands in all areas except a small pocket, that area of the balloon with pouch outward- this is what is happening with your joint. A thin canal of fluid forms and pouches outside the joint.
See a Podiatrist even if it doesn’t hurt. Even though a ganglionic cyst is usually harmless except for the pain, there is always a chance that this could be a cancerous tumor such as a synovial sarcoma(very low odds).
After the aspiration of the ganglion cyst, you will likely be free of the ganglionic cyst for some time; but eventually it is almost guaranteed to come back. The only true cure for a ganglion cyst in the foot is aspiration.
The recovery time depends on a variety of factors, but if it is on the top of the foot(which it almost is), you can start walking almost immediately and take the sutures out in about 2 weeks.