Ganglion cysts are non-cancerous, benign lumps that most commonly develop along the tendons or joints of your wrists or hands and sometimes, the ankles and feet. Ganglion cysts are typically: Oval or round in shape Filled with a jelly-like fluid Painful if pressing on a nearby nerve Pea-sized to around 2.5 cm in diameter The location of your ganglion cysts can sometimes interfere with joint movement. If your ganglion cyst is causing problems, your doctor may suggest draining the cyst with a needle or removing the cyst through surgery. If your ganglion cyst causes no problems, no treatment is necessary, as the cysts usually go away on their own.