Introduction/Background Endometrial hyperplasia (EH) was classified by the World Health Organization in 2014 into two categories based on the presence of cytological atypia .Approximately, 200,000 new cases of EH are diagnosed annually in developed countries .EH is of significant clinical importance, given that it is the precursor of endometrial carcinoma, the most common gynecological cancer in developed countries

Methodology We retrospectively reviewed the medical records of 675 cases with pathology results of nonatypical endometrial hyperplasia and above, out of 1122 patients who underwent endometrial biopsy for abnormal uterine bleeding at two referral hospitals in Ankara between 2015 and 2020. Data were extracted for age, menopausal status, endometrial thickness .presence of breast cancer, use of tamoxifen, symptoms, surgical treatment and histopathology .

Results Data of 675 patients were evaluated. The median age was 47 years (min 24-max 82). Transvaginal ultrasonography results of 530 patients were obtained, median endometrial thickness was 12 mm (min 3- max 40). 526 of the cases were premenopausal, 149 of them were postmenopausal. 12 of 23 cases with breast cancer were using tamoxifen. 32 of 675 cases were asymptomatic, 496 of them were abnormal uterine bleeding. and 143 of them had endometrial biopsy with the diagnosis of postmenopausal bleeding. 164 of the cases were treated surgically.

Conclusion In the evaluation of 1122 patients who underwent endometrial biopsy due to abnormal uterine bleeding, endometrial hyperplasia and higher lesions were detected in 675 (60.16%) cases, and endometrial cancer was observed in 86 (7,66%) of these cases.