Can the endometrial thickness as measured by trans-vaginal sonography be used to exclude polyps or hyperplasia in pre-menopausal patients with abnormal uterine bleeding?

Background. To combine findings of normal mid-line echoes from TVS (trans-v aginal sonography) with cut-off levels for endometrial thickness, in order to examine the associated risk of abnormalities in the uterine cavity. Design and Setting. Two center prospective study at a university clinic and a central hospital in Denmark. Participants. Three hundred and fifty-five pre-menopausal patients with abn ormal uterine bleeding, and indications for endometrial sampling or surgery . Interventions. The thickness of the endometrium was measured, and the mid-l ine echoes were evaluated using TVS. The findings from the endometrial samp ling, combined with the evaluation of the uterine cavity using operative hy steroscopy (115), hysterectomy (74) or HSE (hysterosonographic examination) (166), were used as the true values. Results, The mean (+/-s.d.) endometrial thickness was significantly differe nt in patients with hyperplasia 11.5 mm (+/-5.0), polyps 11.8 mm (+/-5.1), sub-mucous myomas 7.1 mm (+/-3.4) and in patients without these abnormaliti es 8.37 (+/-3.9) (p <0.001). Hyperplasia and/or polyps were present in 20% of all patients, and in 8% of 143 patients with an endometrial thickness of less than or equal to7 mm, This proportion did not decrease with lower cut -off levels for endometrial thickness. Receiver operating characteristic (R OC) curves were not optimal for excluding hyperplasia or polyps by endometr ial thickness. In 173 cases with a distinct, regular midline echo without e cho-dense foci in TVS the proportion of patients with abnormalities was 16% (11-23). This proportion did not decrease with cut-off levels for endometr ial thickness. Conclusions. Using TVS, low levels of endometrial thickness reduced the pos sibility of abnormalities such as polyps and hyperplasia, but did not exclu de them. Low cut-off levels for endometrial thickness did not increase the diagnostic performance in cases with normal sonograms.