Kitty lester, I have had Tarlov cysts on my lower spine for a few years now. They were found after a scan, 5 or 6 of them, they are oblong and showed up white in colour. (For some reason I thought they would be round.). As it seems from other comments although not rare, they appear to be fairly unusual. Like Sheena I have other medical conditions. I have had back pain for years in varying degrees, I have osteo and rheumatoid arthritis, but no-one has suggested an operation. Truth be told, having had numerous other operations, I tend to be very wary of them. However, I would definitely not class my present discomfort with anything your friend is currently suffering, I do sympathise with her. There does seem very little information available, even some medical people don’t seem to have heard of it. My advice for what it is worth, is to explore all other possible causes before opting for surgery, however I have no medical qualifications and only speak from personal experience. Best wishes to your friend.