Determining a threshold measurement of endometrial thickness for asymptomatic postmenopausal women: A tertiary centre case series.

BACKGROUND: An incidental finding of a thickened endometrium on ultrasound in the postmenopausal patient without bleeding is a common presentation to gynaecological services; however there is limited evidence to guide clinical practice as to when hysteroscopic evaluation and endometrial sampling is required. AIMS: To determine the endometrial thickness at which endometrial sampling is indicated in asymptomatic postmenopausal women referred with thickened endometrium on ultrasound. MATERIALS AND METHODS: A single-centre retrospective case series of postmenopausal women without bleeding undergoing hysteroscopy was conducted. Logistic regression was used to examine the association between a range of variables and pre-malignant or malignant pathology and endometrial thickness. The optimal endometrial thickness threshold was identified to maximise model sensitivity. RESULTS: A total of 404 postmenopausal women were included in this study, having undergone a hysteroscopy at the study site between 1 July 2008 and 30 June 2018. The mean (SD) age of patients at presentation was 65 (9.09) years and the mean body mass index was 29.86 kg/m2 (6.52). Of these women, nine (2.2%) were diagnosed with endometrial carcinoma and seven (1.7%) had endometrial hyperplasia with atypia. The most common histopathological finding was of a benign endometrial polyp (153: 37.9%). When including hyperplasia with or without atypia in histopathology of interest, a cut-off of ≥9 mm provides the greatest sensitivity (83.3%) and specificity (63.8%) for a diagnosis of pre-malignant or malignant pathology (classification accuracy of 64.8%; area under the receiver operating characteristic: 0.7358, 95% CI: 0.6439, 0.8278) in this cohort. CONCLUSIONS: Using an endometrial thickness of ≥9 mm can be used as a cut-off for endometrial sampling in postmenopausal women without bleeding.