Impression: abnormally thickened very heterogeneous endometrium up to 1.2 cm maximally on transvaginal imaging i am postmenopausal? i was diagnosed stage 4 metastatic breast cancer with secondary bone. what does all of this mean in lamens terms?

You will need endometrial biopsy for ruling out endometrial cancer, especially if you had this study due to vaginal bleeding. Secondary cancer is more common in a person with a primary cancer compared with a person without history of malignant disease. However, the significance of endometrial hyperplasia may be less if you are on hormone therapy for metastatic breast cancer.