Prevalence and ultrasonographic characterization of newly detected findings suggestive of deep and ovarian endometriosis in postmenopausal women undergoing routine gynecological examination

INTRODUCTION: To assess the prevalence and ultrasonographic characteristics of newly detected findings suggestive of ovarian and deep endometriosis (DE) in postmenopausal women undergoing routine gynecological evaluation. MATERIAL AND METHODS: This prospective observational study (NCT07503938) included consecutive postmenopausal participants attending two regional gynecology outpatient clinics for routine examination over 24 months. Transvaginal ultrasound was performed by a single operator according to International Deep Endometriosis Analysis (IDEA) group criteria. Findings suggestive of DE and/or ovarian cysts suggestive of endometriomas were recorded and characterized. Clinical data were collected using a structured questionnaire. Univariable and multivariable logistic regression identified factors associated with posterior compartment hypoechoic nodules. RESULTS: Four hundred ninety-two participants were included (mean age 60.2 ± 6.1 years; median time since menopause 8.0 years). Ultrasound findings suggestive of endometriosis were identified in 40 participants (8.1%; 95% CI 5.9%-10.9%), including posterior compartment hypoechoic nodules in 36 (7.3%). Intestinal nodules (n = 21; 4.3%) often showed plaque-like morphology, thickness < 7 mm, regular margins, limited Doppler vascularity, and uncommon submucosal involvement. The prevalence of posterior nodules suggestive of DE decreased with increasing time since menopause (13.9% within ≤5 years vs. 4.3% >10 years; p for trend = 0.001). In multivariable analysis, ≤5 years since menopause was independently associated with posterior nodules (adjusted OR 3.25, 95% CI 1.35-7.83), as were 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). No independent association was observed with current pelvic pain, dyschezia, previous infertility, or systemic hormone replacement therapy. Six ovarian cysts with ultrasonographic features suggestive of endometriomas were identified (1.2%; 95% CI 0.45%-2.64%), five of which exhibited atypical features, including multilocularity, heterogeneous echoes, papillary excrescences, or wall thickening. CONCLUSIONS: Ultrasound findings suggestive of DE may be detected after menopause and are associated with earlier postmenopausal timing and a history of reproductive-age pain, but not with specific current pain symptoms or hormonal exposure. Their predominantly plaque-like, poorly vascularized morphology may reflect fibrotic remodeling, although histological composition and biological activity cannot be established by ultrasound alone. Expert ultrasound remains important to distinguish benign-appearing residual findings from clinically relevant or malignant pathology.