Actually, I've had two Bakers Cysts (popliteal cysts) in the past few years. My most recent, and most troubling, was in November 2018. The damned thing landed me in the hospital -- although I told the E.R. doctor that it was a Bakers Cyst (I take warfarin, and knew what the cyst was like) he was afraid it was Compartment Syndrome - and admitted me for observation. A few days later, I saw a Rheumatologist who drained the knee every week or so, until I had some flexibility return to the joint.
What happened this time was nothing like the Bakers Cyst -- it was in the other leg, and was a mobile mass that passed under the patella. I could feel it slightly above the right knee, and move it under the knee, to the other side of, and below the patella. It seemed to change the geometry between lower leg and knee, causing new muscles to work, and creating muscle pain. At its worst, I could barely bend my leg. Fortunately, this has eased up quite a bit.
Thanks for the speculation of a Bakers Cyst -- but what I had was nothing like one.