A ganglion cyst is a round or oval, fluid-filled lump that most commonly develops along the tendons or joints of the wrists, hands, ankles, or feet. On ultrasound, a ganglion cyst typically appears as a well-defined, anechoic or hypoechoic structure with posterior acoustic enhancement, often with a visible stalk or neck connecting it to an adjacent joint or tendon sheath. Ganglion cysts are the most common soft tissue mass of the hand and wrist and are completely benign. Ultrasound not only confirms the diagnosis but can also guide aspiration, a treatment in which a needle is inserted into the cyst to withdraw the thick, jelly-like fluid inside.
Sonography Term