Introduction/Background Endometrial intraepithelial neoplasia (EIN) is a premalignant lesion, but risk of concurrent endometrial adenocarcinoma (EAC) is also high. Although most patients with EIN diagnosed with concurrent EAC will have low risk disease, some will have high-risk disease who require. Clinical characteristics may help determine such patients.

Methodology Patients with a diagnosis of EIN who were operated at Hacettepe University Faculty of Medicine, Department of Obstetrics and Gynaecology were identified. The rate of concurrent EAC and high-risk EAC were determined. Preoperative characteristics were reviewed in order to determine the predictors of concurrent malignancy.

Results A total of 252 patients constituted study group. Mean age was 46.6 years and 43.7% were postmenopausal. 44.0% had co-existing one or more medical diseases while 14.3% had diabetes, 19.5% had hypertension, and 7.5% had both. The most common surgery was total hysterectomy with or without adnexal removal performed in 93.6% of patients. Frozen section was requested for 82.5% of patients. Final pathology revealed EAC in 17.5%, but only 4.4% had high-risk disease. The accuracy of frozen section for predicting final pathology in terms of the presence or absence of EAC was 89.4%. Patient with malignancy tend to be significantly older (47.4 vs. 54.1 years, p=0.02) and risk of malignancy was significantly higher in postmenopausal women (9.2% vs 28.2%, p<0.001) and in women with hypertension (13.8% vs 32.7%, p=0.02). similarly, patients with high-risk disease were significantly older (48.2 vs. 58.2 years, p=0.01) and this risk was higher in postmenopausal women (1.4% vs. 8.2%, p=0.01) and women with hypertension (3.0% vs. 10.2%, p=0.04).

Conclusion Surgery is the mainstay of treatment in patients with EIN. During surgery, frozen section evaluation should be requested since a significant proportion of patients have concurrent EAC and frozen section is highly effective in determining these patients. Although rare, some patients may have concurrent high-risk endometrial carcinoma necessitating surgical staging. Both concurrent invasive carcinoma and high-risk disease are associated with older age, being in postmenopausal period, and having hypertension.

Disclosures No potential conflict of interest to declare.