A synovial cyst located behind the knee is known as which?

• A. Baker cyst
• B. Ganglion cyst
• C. Popliteal aneurysm
• D. Meniscal cyst

Answer: (A)

A Baker cyst is a synovial cyst that arises in the popliteal fossa, behind the knee. It typically forms from the gastrocnemius–semimembranosus bursa and can communicate with the knee joint, often appearing in the setting of intra-articular pathology such as arthritis or a meniscal tear. This location and origin make it the classic posterior knee cyst.

Ganglion cysts can occur near joints but are not characteristically located behind the knee. A popliteal aneurysm is a vascular dilation and presents as a pulsatile mass with potential vascular symptoms. A meniscal cyst is associated with a meniscal tear and sits at the joint line near the meniscus rather than in the posterior knee behind the joint.