I am really not that familiar with uterine cancer. Did your doctor have recommendations. In general, the size of your nodule seems very small and may be able to be watched over time. An endometrial biopsy is relatively easy (I've had two of them). This would be able to rule out a malignancy at this time. You should talk to your doctor abotu this issue. Your nodule does have some complexity since it is hypoechoic. Your doctor is the best one to advise you on this matter!