OC08.06: Ability to adequately visualise an endometrial echo on transvaginal ultrasound in asymptomatic postmenopausal women

Postmenopausal bleeding (PMB) is considered “endometrial cancer (EC) until proven otherwise." Numerous studies indicate that an endometrial (EM) echo of ≤ 4 mm on transvaginal ultrasound (TV U/S) is a reliable enough test to exclude EC such that biopsy is not needed in initial cases of PMB. However, not all PM women will have anatomy that lends itself to a meaningful determination of EM thickness. This study was undertaken to evaluate the frequency of, and reasons for, an inability to adequately visualise an EM echo. 261 consecutive asymptomatic PM women had TV U/S as part of routine gynecologic care. Their charts and TV U/S were reviewed by a single observer (SG), and, if adequate, EM thickness was recorded. When it was not well visualised the reason for inadequacy was recorded. Demographics included years since menopause and BMI. Of the 261 women, 157 (60.2%) had an EM echo that was well visualised and reliably measured (mean 3.2 mm, range 1.0 -27.0) In 104 PM women (39.8%), a distinct measurable EM echo was not adequately visualised. Reasons were: Fibroids (n = 53, or 20.3% of overall cohort), Adenomyosis (n = 16, or 6.1% of overall cohort), Axial uterus (n = 35, or 13.4% of cohort). Mean years since menopause was 14.0 in those visualised (range 1-50), and 13.2 in non-visualised (range 1-40) (N.S.). Mean BMI was 24.1 in visualised (range 16–41) and 25.6 (range 15–40) in non-visualised (p = .015). TVUS has become an accepted first step in PMB. However, not all uteri lend themselves to a meaningful determination of EM thickness. In this cohort 39.8% of women had anatomic reasons for non-visualisation of a reliable EM measurement e.g. fibroids, adenomyosis, and axial uterus. There was no significant difference between groups based on years since menopause but the mean BMI of the non-visualised group was significantly higher than those visualised. Clinicians should be cognisant of these potential limitations of TV U/S in the initial evaluation of women with PMB.