Patients are randomized to 1 of 3 treatment groups. Patients will receive MA (megestrol acetate) 160 mg by mouth daily for at least 3 months on Arm I. Patients will receive LNG-IUS insertion on Arm II and MA 160 mg plus LNG-IUS insertion on Arm III. Then an hysteroscope will be used to evaluate the endometrial condition every 3 months, and the findings will be recorded. For patients with EAH, complete response (CR) is defined as the reversion of endometrial atypical hyperplasia to proliferative or secretory endometrium; partial response (PR) is defined as regression to simple or complex hyperplasia without atypia; no response (NR) is defined as the persistence of the disease; and progressive disease (PD) is defined as the appearance of endometrial cancer in patients. Continuous therapies will be needed in PR, NR or PD.