This is frightening stuff and your emotions are right where they should be especially since you have a family history.
I am very glad they caught this issue now. Sounds like you are in good hands medically.
I know hormones and cancer do not mix and am aware of the challenges you would face should a total hysterectomy be deemed necessary. But lets stay positive that this thing is benign. That is the thought and prayer I will hold on to for you. Hugs