Endometrial cells in cervix

I got a normal smear result but was then phoned and told I had endometrial cells in sample and as I was over 50 I needed to be referred. I don’t know why I’m being referred - any help?

Hi, 

 I've recently had the Lletz treatment for Cin3 and was then told in results letter that they had found endometrial cells aswell as the Cin3 cells. The consultant has now referred me for a hysteroscopy to see what's going on in my uterus.  Lol not much help but just wanted to say your not alone! X