So, you had a pap and they found you had the polyps and abnormalities? This is not uncommon and they are typically precancerous and they often 'freeze' them off. Or are you saying you had an actual biopsy done? I do think a biopsy is done on other things to see if there is cancer present. I had a biopsy of calcifications in my breast for example to see if there was cancer present (there wasn't, thank goodness). So, I had something suspicious, they removed it and tested it to see if it was cancer. This is probably what you mean by biopsy?
A biopsy is merely the word for when they remove a little bit of tissue so they can send it to the lab to diagnose a condition. The endometrium is the lining of the uterus. An endometrial biopsy is the removal of a little bit of the endometrial tissue to send it to the lab and see what is going on. It is not a test for cancer, it's a diagnostic tool for whatever is there.