Transvaginal ultrasonography of the endometrium in women with postmenopausal bleeding: Is it always necessary to perform an endometrial biopsy?

Ojective: This study was undertaken to evaluate whether it was possible to abstain from performing an endometrial biopsy when endometrial thickness according to transvaginal ultrasonography was ≤4 mm in women with postmenopausal bleeding or irregular bleeding during hormone replacement therapy. Study Design: Transvaginal ultrasonography was performed in 361 women aged ≥50 years who were referred because of postmenopausal bleeding or irregular bleeding during hormone replacement therapy. If endometrial thickness was ≤4 mm, a Papanicolaou cervical smear was performed and the woman was reexamined with transvaginal ultrasonography after 4 and 12 months. Subjects were also instructed to return if they had recurrent bleeding, in which case transvaginal ultrasonography was performed and an endometrial biopsy specimen was obtained. Women with an endometrial thickness ≥5 mm underwent either curettage or endometrial biopsy. Results: One hundred sixty-three women had an endometrial thickness ≤4 mm. In this group one endometrial cancer that was missed by ultrasonography was diagnosed by cervical cytologic examination and two adnexal malignancies were diagnosed by uttrasonography. Endometrial malignancy was diagnosed in 0.6% of the women with an endometrial thickness ≤4 mm. Endometrial biopsy was performed because of recurrent bleeding in 6.1 % of cases and because of endometrial thickening in 8.1 %. No cancer or hyperplasia was subsequently diagnosed among the women with an endometrial thickness ≤4 mm. Endometrial cancer was diagnosed in 18.7% of the women with an endometrial thickness ≥5 mm. The corresponding figure when atypical hyperplasia and endometrial metastases were included was 20.2%. Conclusions: If the false-negative rate of endometrial biopsy techniques is taken into account, then the combination of transvaginal ultrasonography and cervical cytologic examination is an adequate form of management for women with postmenopausal bleeding or irregular bleeding during hormone replacement therapy as long as endometrial thickness is ≤4 mm. A randomized prospective study is necessary to verify this finding.