Study Finds Possible Deep Endometriosis in 7% of Postmenopausal Women

Ultrasound findings suggestive of deep endometriosis (DE) were detected in 7.3% of postmenopausal women with no prior diagnosis who were undergoing routine gynecologic examinations, according to a prospective study in Acta Obstetricia et Gynecologica Scandinavica.¹

Endometriosis has long been viewed as a condition of the reproductive years because it depends on estrogen. The 2022 European Society of Human Reproduction and Embryology (ESHRE) guideline addresses endometriosis in postmenopausal women.² However, the study authors noted that most of what is known comes from case reports, small surgical series, and autopsy findings, and that the ultrasound appearance of the disease after menopause had not been systematically described.¹

Study Design and Prevalence

Investigators enrolled 492 consecutive women who had undergone spontaneous menopause and attended 2 regional gynecology clinics in the Genoa, Italy, area between June 2023 and June 2025. Women with a prior radiological or surgical diagnosis of endometriosis were excluded. The mean age was 60.2 years, and the median time since menopause was 8.0 years. A single expert operator performed transvaginal ultrasound using International Deep Endometriosis Analysis group criteria.

Findings suggestive of endometriosis, either posterior nodules or endometrioma-like ovarian cysts, appeared in 40 women (8.1%; 95% CI, 5.9%-10.9%). Of the total women, 36 (7.3%) had nodules in the posterior compartment suggestive of DE, most often at the uterosacral ligaments and uterine torus (19 sites) or the rectum (15 sites). Among 21 intestinal nodules, most had a plaque-like shape, 18 were thinner than 7 mm, 17 had regular margins, and the nodules often showed limited Doppler vascularity. Ultrasound showed no submucosal involvement in 16 of the 21 lesions.

Timing and Pain History

Nodule prevalence fell with time since menopause, from 13.9% within 5 years to 4.5% at 6 to 10 years and 4.3% beyond 10 years (P for trend = .001). In multivariable analysis, women within 5 years of menopause had higher adjusted odds of posterior nodules than those more than 10 years out (adjusted OR, 3.25; 95% CI, 1.35-7.83). A history of dysmenorrhea (adjusted OR, 2.20; 95% CI, 1.05-4.60) and chronic pelvic pain (adjusted OR, 2.36; 95% CI, 1.11-5.00) during reproductive years were also independently associated with nodules.

Current pelvic pain, dyschezia, prior infertility, and systemic hormone replacement therapy were not independently associated with nodules. The authors said the estimate for hormone therapy was imprecise and should not be read as evidence of no hormonal effect. They also cautioned that the time-since-menopause pattern is cross-sectional and should not be read as lesions regressing within individual women.

Atypical Cysts and Malignancy

Six ovarian cysts (1.2%) had features suggestive of endometriomas, and 5 were atypical, with multilocularity, heterogeneous echoes, papillary projections, or wall thickening. Three women with atypical cysts were referred for surgery because of their postmenopausal status and the cysts' appearance, and in one case, an elevated cancer antigen 125 (CA125) level. Histopathology confirmed benign endometriosis-related pathology in 2. The third lesion, thought to be an atypical endometrioma, was a stage I serous borderline ovarian tumor.

Separately, one woman with rectal bleeding had a rectal lesion that ultrasound could not classify as DE. Colonoscopy found rectal adenocarcinoma, with no evidence of endometriosis.

“Expert ultrasound remains important to distinguish benign-appearing residual findings from clinically relevant or malignant pathology,” the authors concluded.

Limitations

Because histology was rarely obtained, lesion characterization is presumptive. The operator was not blinded to clinical history, and morphologic descriptors were assessed post hoc, although a blinded second reader showed high agreement for posterior nodules (Cohen's κ = 0.92). The regression analyses were exploratory, and reproductive-age symptoms were self-reported retrospectively. Participants came from regional clinics, so the prevalence applies to newly detected findings in this setting, not to postmenopausal endometriosis overall.

References

1. Barra F, Perrone U, Xholli A, et al. Prevalence and ultrasonographic characterization of newly detected findings suggestive of deep and ovarian endometriosis in postmenopausal women undergoing routine gynecological examination. Acta Obstet Gynecol Scand. 2026;00:1-13. doi:10.1111/aogs.70383
2. Becker CM, Bokor A, Heikinheimo O, et al. ESHRE guideline: endometriosis. Hum Reprod Open. 2022;2022(2):hoac009. doi:10.1093/hropen/hoac009