Can anyone tell me about synovial cysts?

I hope I’ve put this in the right forum.

My mother found out that she has a synovial cyst on her spine, earlier this year. She went over treatment options with her doctor, and they went for some kind of steroid injection. That was 3 months ago, and now she needs another steroid injection as the first wore off.

I know it’s possible to have one of these surgically removed - is this surgery being done with lasers? Her mother had a tumor removed from her spine and spent the remainder of her life partially paralyzed. That was more than 40 years ago; I hope they’ve gotten better at it since then.