I went through something like that when I had an ovarian cancer scare a few years ago. It turned out I actually had something else, but it was something that they apparently couldn't/can't diagnose outside of examining the uterus in the pathology lab...

I learned then that I have to be very careful how much medical research I can do online - without a medical background it is difficult to tell the wheat from the chaff and it is so easy to jump to the big "C"...especially if someone from the doctor's office has already put it in your head! I can understand what your sister went through, so glad to hear the results though.