Prevalence of occult endometrial carcinoma in patients with endometrial intraepithelial neoplasia who underwent hysterectomy

OBJECTIVES: To determine the prevalence of occult endometrial carcinoma in patients with endometrial intraepithelial neoplasia (EIN) post-hysterectomy and identify pre-hysterectomy risk factors predictive of occult carcinoma. METHODS: This retrospective study included patients diagnosed with EIN between 2007 and 2021 who underwent hysterectomy as primary treatment. An expert gynecologic pathologist reviewed pathological slides. Data collected from medical records included demographic and gynecologic information, sonographic findings, and surgical and pathological outcomes. The prevalence of occult endometrial carcinoma was calculated. Descriptive statistics evaluated carcinoma incidence, and logistic regression analysis identified independent risk factors. RESULTS: A total of 113 patients were evaluated. The median time to hysterectomy was 9.1 weeks (range 5.8-12.8 weeks). Post-hysterectomy, 36 patients (31.8%) were diagnosed with endometrial carcinoma, all endometrioid type. Of these, 88.9% were stage I per the International Federation of Gynecology and Obstetrics classification system, and 11.1% were at high risk for nodal metastasis. Predictive factors for occult carcinoma included the intraoperative gross lesion size (2 cm or larger and less than 2 cm) and endometrial aspiration. Adjusted odds ratios were 6.723 (95% CI 2.338 to 19.333) for lesions 2 cm or larger, 3.381 (95% CI 1.128 to 10.132) for lesions less than 2 cm, and 2.752 (95% CI 1.092 to 6.936) for endometrial aspiration. CONCLUSIONS: Occult endometrial carcinoma was identified in 31.8% of patients with a pre-hysterectomy EIN diagnosis. The significant predictors were endometrial aspiration and the presence of a gross lesion during surgery.