Thanks for providing additional information.
As per your description,potential differential diagnosis may include Herniated disc,Lumbar radiculopathy,Progressive nature of degenerative cyst over the time.
Synovial cyst develops when facet joints degenerate in the lower lumbar spine and it is common known degenerative cyst however you need to check it in your MRI reports.
Synovial cyst can cause pain (sometimes significant pain) because they irritate of the nerve roots and this cyst may grow in size as the fluid accumulates gradually over the time.
There is really nothing that can stop it from growing.
Sometimes the cyst (near the facet joint) can be drained if it is accessible and at the same time corticosteroid can be injected to reduce inflammation and hence the pain.
Surgical procedure is done if the cyst cannot be easily accessed or there are other factors that make drainage alone sub-optimal.
Surgery can be done by microdecompression and for patients with spine instability, decompression with fusion.
In my opinion,you need to be seen by your doctor again for a clinical examination and further repeat MRI should be done to screen the current condition of cyst and other degenerative changes in the surroundings.
Your pain'll not permanently relieve with Tylenol.
So make an appointment with your doctor in next few days.
Hope this helps.
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