Could Vaginal Discharge Be Due To Senile Endometriosis?

sir,my mother is 60 yrs old she is a known hypertensive and diabetic.her random blood sugar is 116 mg/dl and her bp is 140/90 mm hg.she is taking tab.metformin 500mg od and tab.atenolol 25 mg od.she had her menopause at 52 yrs.she is uniparous.now for past 3 yrs she is having a brownish non foul smelling vaginal discharge,her pap smear test is negative and her d&c report is also negative.sir colud this discharge be due to senile endometritis or is there a possibility of endometrial cancer.what is the diagnostic test for it?sholu we proceed for diagnostic hysteroscopy?