The prevalence of occult endometrial cancer in women undergoing hysterectomy for benign indications.

Objective: To estimate the frequency of occult endometrial cancer in women undergoing hysterectomy for benign indications.

Study Design: We performed a retrospective review of all patients undergoing hysterectomies for benign indications at our institution from 2006 to 2014. A departmental database was used to identify all hysterectomies performed, and institutional tumor registry was used to identify cases of endometrial carcinoma. Occult carcinomas were defined as cases with no suspicion preoperatively and histopathologic diagnosis of endometrial cancer postoperatively.

Results: A total of 6981 hysterectomies were performed for benign indications. Among these, thirteen patients (0.19%) were found to have occult endometrial cancer, with an overall rate of 1 in 537 patients (95% confidence interval 1:314-1:1008). Twelve patients had stage IA and one had stage IB disease. Median age of women found to have endometrial cancer was 50 years (range 35-72 years). The median BMI was 29.8 kg/m (range 21.3-50.4 kg/m). The most common indications for hysterectomy were abnormal bleeding (47%), postmenopausal bleeding (15%), adnexal mass (15%), prolapse (15%), and endometrial hyperplasia without atypia (8%). Of the postmenopausal women that had bleeding, all patients underwent evaluation of the endometrium, however 75% of samples did not have adequate amount of endometrium to be evaluated and 25% were found to have hyperplasia.

Conclusion: This is one of the largest single institution cohorts to examine occult malignancy. Unexpected endometrial carcinomas were found to occur in 0.19% or 1:537 (95% confidence interval 1:314-1:1008) hysterectomies for benign indications in our population. PRéCIS: Occult endometrial carcinomas are found to occur in 1:537 (0.19%) hysterectomies for benign indications.