Hysteroscopic Inspection and Total Curettage Are Insufficient for Discriminating Endometrial Cancer from Atypical Endometrial Hyperplasia

: Endometrial cancer (EC) is the most prevalent gynecologic malignancy in Japan. Atypical endometrial hyperplasia (AEH) is viewed as the premalignant lesion of EC, however it is often difficult to distinguish EC from AEH. The rate of concurrent EC in women diagnosed preoperatively with AEH based on endometrial biopsy was reported as 17-52%. Although hysteroscopic inspection and total curettage are considered as useful methods to make diagnosis of endometrial lesions, there is no report using this combined method to discriminate EC from AEH. The purpose of this study was to examine whether hysteroscopic inspection and total curettage improve the prevalence of EC among women diagnosed preoperatively with AEH. We reviewed 22 patients who underwent hysteroscopic inspection and total curettage and were diagnosed with AEH before undergoing hysterectomy between November 2001 and May 2011. The diagnosis made with the hysterectomy specimens revealed AEH in 10 patients (45.5%), endometrial hyperplasia without atypia in 3 (13.6%), and endometrioid adenocarcinoma, the most common type of EC, in 9 (40.9%). Endometrioid adenocarcinoma included 7 patients without myometrial invasion (31.8%) and 2 patients with superficial myometrial invasion (9.1%). There was no hysteroscopic finding that was specific for EC or AEH. In conclusion, about 41% of women who underwent hysterectomy under a diagnosis of AEH were found to have coexisting adenocarcinoma, although the prevalence of EC among those women was similar to that in earlier reports with endometrial biopsy. Accordingly, we must be careful in planning the therapeutic strategy for women with a preoperative diagnosis of AEH.