<prompt> Bakers cyst is a type of -Pulsion diveiculum of knee jointRetention cystBursistisBenign tumor  <response>: It is the pulsion diveiculum of the knee joint, caused by chronic disease in the joint. Bulging of the posterior capsule and synol herniation may produce a swelling in the popliteal fossa. It fluctuates but is not tender. REF:Apleys 9the p.578-9 