Popliteal Cyst
A SYNOVIAL CYST located in the back of the knee, in the popliteal space arising from the semimembranous bursa or the knee joint.
Synovial Cyst
Non-neoplastic tumor-like lesions at joints, developed from the SYNOVIAL MEMBRANE of a joint through the JOINT CAPSULE into the periarticular tissues. They are filled with SYNOVIAL FLUID with a smooth and translucent appearance. A synovial cyst can develop from any joint, but most commonly at the back of the knee, where it is known as POPLITEAL CYST.
Cysts
Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.