Can concurrent high-risk endometrial carcinoma occur with atypical endometrial hyperplasia?

Background: This study investigated the frequency of high-risk cancer types in hysterectomy material obtained from patients who were diagnosed with atypical endometrial hyperplasia (AEH) by endometrial sampling. Materials and methods: A total of 227 patients with AEH were retrospectively included in the study. Hysterectomy material was examined as both perioperative frozen section (FS) and paraffin-embedded permanent section (PS). Grade III tumors, grade II tumors larger than 2 cm, over 50% myometrial invasion, cervical involvement, and serous or clear cell histology were considered high-risk. Results: In final pathology, 57 (25.1%) patients had endometrial cancer and 7 (3%) patients had high-risk cancer. Overall analysis of FS/PS agreement yielded a Cohen's Kappa (K) coefficient of 0.420 (moderate agreement). There was moderate (K=0.526) agreement between FS and PS in detecting tumor grade, and good agreement (K=0.653) in evaluation of myometrial invasion. Conclusion: High-risk endometrial cancer can coexist with AEH. It should be remembered that despite pre-operative and FS examinations, these high-risk tumors can be overlooked until final pathology.