Hi Barb D., Metastasis could be the culprit. Also after a two day ordeal in the hospital, I discovered that fluid retention build-up can cause incredible pain in that area, to the point of not being able to walk without causing pain. Regular x-rays can determinr fluid retention. In my case it was being monitored and treated with lasix for approximately four months. It was thought there was not enough fluid to cause any significant pain. Well, after they drained what did not look like much, 1 1/2 liters, the pain went from 9-10 down to 1-2 in the lower back kidney area. Just to much fluid creating to much pressure on so many nerves. Just one suggestion to keep an eye on or check out. Fluid retention can be caused by the disease.
Take it to the Limit,One More Time! (Eagles)