In 2004, after beating cancer twice, out of nowhere Reba Kennedy of Knoxville, Tenn., began experiencing constant, agonizing pain.

"We went several times to the doctor and they checked every way they knew how, but didn't see anything," she says. "But I knew that I was just in so much pain."

Finally, during a routine check-up with her oncologist they found the source -- a large mass wrapped around...