Atraumatic intra-articular, extra-synovial ganglion cyst of the lateral knee deep to the iliotibial band: A case report and review of the literature.

Ganglion cysts are mucin-filled synovial cysts commonly found on the dorsal surface of the hands and feet. Intra-articular ganglion cysts of the knee are rare, and when they present clinically, are typically treated operatively through arthroscopic surgery. We present the first reported case of an atraumatic intraarticular, extra-synovial ganglion cyst of the lateral knee located deep to the iliotibial band that was successfully treated without operative intervention through repeated intra-articular aspirations of the knee.