Objective: Patients with endometrial intraepithelial neoplasia may have concurrent endometrial cancer if managed surgically or develop cancer in time if managed conservatively. Therefore, intraoperative assessment of the uterus may be helpful if a surgical approach is decided on. Our study aimed to investigate the role of frozen-section examination in patients with endometrial intraepithelial neoplasia.

Material and Method: Patients with endometrial intraepithelial neoplasia who were subjected to hysterectomy with intraoperative frozen-section assessment were included. Main outcome measures were the rates of concurrent endometrial cancer and concurrent high-risk endometrial cancer as well as the efficacy of frozen-section in the detection of concurrent invasive disease and in the designation of low-risk and high-risk features.

Results: The study group consisted of seventy-three patients. Permanent pathology revealed endometrial adenocarcinoma in 19.2% whereas only one patient (1.4%) had high-risk disease necessitating surgical staging. Frozen-section diagnoses were consistent with final pathology in 93.2% of patients in terms of the presence or absence of co-existent carcinoma. When frozen-section reports were further evaluated in terms of the presence or absence of high-risk endometrial carcinoma, consistency with the final pathology was seen in 98.6% of patients.

Conclusion: Co-existent endometrial cancer is not uncommon in endometrial intraepithelial neoplasia. Intraoperative frozen-section evaluation should therefore be considered whenever possible. Frozen-section is effective in the detection of coexistent invasive disease and in the designation of low-risk features. Although coexistent high-risk cancer is extremely rare, frozen-section assessment is not successful in determining high-risk features. Therefore, a re-staging surgery may be required on rare occasions.