My pap smear was negative for hpv but showed endometrial cells?what does this mean?my dr. wants to do a biopsy.

It's a precaution: Endometrial cells come from your uterus. In women your age, about 12% show normal endometrial cells on their pap smear. Usually they are just normal cells that have "shed" into your pap smear. But about 1 in 10 times they can signal something abnormal is happening in your uterus, possibly cancer. It's recommended that any woman with these cells on a pap smear has further testing, just to be sure.