Comparative diagnostic accuracy of office hysteroscopy and three-dimensional transvaginal ultrasonography versus histopathology in women with abnormal uterine bleeding

Background and aim: Abnormal uterine bleeding (AUB) is a common gynecological complaint with significant clinical and quality-of-life implications. Accurate diagnosis of the underlying pathology is critical to guide management. While three-dimensional transvaginal ultrasonography (3D TVUS) offers non-invasive evaluation of the uterine cavity and myometrium, hysteroscopy remains the gold standard for direct visualization. This study evaluated the diagnostic performance of 3D TVUS and hysteroscopy in women presenting with abnormal uterine bleeding, using histopathology as the reference standard. Methods: This prospective observational cross-sectional study included 80 women presenting with AUB at Cairo University Hospital between June 2021 and April 2023. All participants underwent 3D TVUS, office hysteroscopy, and histopathological evaluation where applicable. Formal comparative analysis with hysteroscopy was restricted to intracavitary lesions, while myometrial lesions were evaluated primarily by TVUS. Diagnostic performance metrics (sensitivity, specificity, PPV – positive predictive value, NPV – negative predictive value, and accuracy) were calculated for individual lesions, overall pathology versus normal, and endometrial cavity lesions. Results: The mean age of participants was 38.6 ± 9.8 years; menorrhagia (30%) was the most common presentation. Endometrial polyps (20%), adenomyosis (17.5%), and intramural fibroids (15%) were the leading pathologies. TVUS showed superior performance for myometrial lesions, with the highest accuracy for intramural fibroids (92.5%). Hysteroscopy was more accurate for intracavitary lesions, particularly hyperplasia (97.5%) and intrauterine adhesions (98.8%). For overall pathology versus normal, TVUS demonstrated higher sensitivity (97.1%) and accuracy (93.8%), while hysteroscopy offered greater specificity (80.0%) but lower NPV (40.0%). Conclusion: 3D TVUS and office hysteroscopy are complementary diagnostic modalities in AUB. TVUS is superior for myometrial lesions, while hysteroscopy remains more accurate for intracavitary pathology. A combined approach offers the most comprehensive diagnostic strategy, optimizing accuracy and minimizing unnecessary invasive procedures. Key words: abnormal uterine bleeding – three-dimensional transvaginal ultrasonography – office hysteroscopy – endometrial pathology – diagnostic accuracy